U.S. patent application number 12/688026 was filed with the patent office on 2010-05-06 for ink unit including ink and ink-wetted member.
This patent application is currently assigned to FUJIFILM CORPORATION. Invention is credited to Kiyoshi MORIMOTO.
Application Number | 20100110153 12/688026 |
Document ID | / |
Family ID | 37854633 |
Filed Date | 2010-05-06 |
United States Patent
Application |
20100110153 |
Kind Code |
A1 |
MORIMOTO; Kiyoshi |
May 6, 2010 |
INK UNIT INCLUDING INK AND INK-WETTED MEMBER
Abstract
An ink unit comprising an ink utilized for an inkjet recorder;
and a wetted member that contacts with the ink, wherein the ink
comprises a pigment dispersedly held in a medium, and the pigment
contains particles having a size of 200 nm or larger in 2 volume
percent or less, and wherein a principal component of the
ink-wetted member is a polyolefin produced by addition of a
phenolic anitoxidant.
Inventors: |
MORIMOTO; Kiyoshi;
(Ashigarakami-gun, JP) |
Correspondence
Address: |
BUCHANAN, INGERSOLL & ROONEY PC
POST OFFICE BOX 1404
ALEXANDRIA
VA
22313-1404
US
|
Assignee: |
FUJIFILM CORPORATION
Tokyo
JP
|
Family ID: |
37854633 |
Appl. No.: |
12/688026 |
Filed: |
January 15, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11517271 |
Sep 8, 2006 |
7673963 |
|
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12688026 |
|
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Current U.S.
Class: |
347/85 ;
347/100 |
Current CPC
Class: |
C09D 11/322 20130101;
C09D 11/40 20130101 |
Class at
Publication: |
347/85 ;
347/100 |
International
Class: |
B41J 2/175 20060101
B41J002/175 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 12, 2005 |
JP |
2005-263669 |
Claims
1. An ink unit comprising: an ink utilized for an inkjet recorder;
and a wetted member that contacts with the ink, wherein the ink
comprises a pigment dispersedly held in a medium, and the pigment
contains particles of 200 nm or larger in 2 percent by volume or
less, and wherein a principal component of the ink-wetted member is
a polyolefin produced by addition of a phenolic antioxidant.
2. The ink unit according to claim 1, wherein the pigment is one of
CI Pigment Yellow-12, CI Pigment Yellow-17, CI Pigment Yellow-55,
CI Pigment Yellow-74, CI Pigment Yellow-97, CI Pigment Yellow-120,
CI Pigment Yellow-128, CI Pigment Yellow-151, CI Pigment Yellow-155
and CI Pigment Yellow-180.
3. The ink unit according to claim 1, wherein the pigment is one of
CI Pigment Red-122, CI Pigment Violet-19, CI Pigment Red-57:1, CI
Pigment Red-146 and CI Pigment Blue-15:3.
4. The ink unit according to claim 1, wherein the ink is an ink set
comprising at least a black ink, a cyan ink, a magenta ink and a
yellow ink, and wherein all of the black ink, the cyan ink, the
magenta ink and the yellow ink contain a pigment dispersedly held
in a medium, and the pigment contains particles of 200 nm or larger
in 2 percent by volume or less.
5. The ink unit according to claim 1, wherein the pigment contains
particles of 200 nm or larger in 1 percent by volume or less.
6. The ink unit according to claim 1, wherein the pigment contains
particles of 200 nm or larger in 0.5 percent by volume or less.
7. The ink unit according to claim 1, wherein the polyolefin is a
polypropylene.
8. The ink unit according to claim 1, wherein the ink-wetted member
is an ink-wetted member of at least one of an ink tank and an ink
cartridge.
9. The ink unit according to claim 1, wherein the ink-wetted member
is an ink-wetted member of an ink absorber.
10. The ink unit according to claim 1, wherein the ink-wetted
member is an ink-wetted member of at least one of a tube of an ink
supply system, a common flow passage of a head, a pressure chamber
of a head and a nozzle of a head.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser.
No. 11/517,271 filed on Sep. 8, 2006, which claims priority to
Japanese Application No. 2005-263669, filed on Sep. 12, 2005, the
entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an ink absorber for use in
an inkjet recorder having an ink-ejection type recording head, an
ink-wetted member such as an ink tank, an inkjet cartridge, and the
like, as well as to ink.
[0004] 2. Description of the Related Art
[0005] A hitherto-known, so-called inkjet recorder has a recording
head of ink ejection type provided with ejection ports for ejecting
ink, and ejects ink in the form of ink droplets from the recording
head to thus cause the ink to adhere to a sheet, thereby recording
an image. The inkjet recorder has an ink tank for storing ink, and
ink is supplied from the ink tank to the recording head. A member
which remains in wetted contact with ink at all times has
heretofore been formed from resin materials, metallic materials,
rubber materials, and the like. In view of cost and ease of
processing, resin materials are often used. Example resin materials
include polyolefins such as polypropylene and polyethylene,
polyvinyl chloride, polyvinylidene chloride, silicone, an
ethylene-vinyl acetate copolymer, ABS, polyacetal, nylon,
unsaturated polyester, aramid, PS, PET, PVC, and the like. In view
of environmentally-friendly recycling, polyolefin such as
polypropylene and polyethylene is preferably used.
[0006] There may be a case where antioxidant is added to a resin
material in order to prevent decomposition and deterioration of the
resin material, which would otherwise be caused when the resin
material is oxidized by heat, light, oxygen, or the like, during or
after the process of manufacturing or processing the resin
material. In order to capture radicals which grow during a stage of
initial chain growth induced by auto-oxidation of a resin material,
in a known technique an antioxidant (e.g., phenolic antioxidant,
amine-based antioxidant, phosphorus antioxidant, thioether oxidant)
has been added.
[0007] In relation to a material having a high degree of
crystallinity such as polyolefin; e.g., polypropylene,
polyethylene, and the like; particularly, polypropylene, crystal of
a molded article is generally nonuniform, scatters light, and
exhibits insufficient transparency. In order to generate a minute,
uniform crystal, a bis(p-methylbenzylidene)sorbitol (trade name:
Gelol MD) has hitherto been known to be added as a crystallization
nucleating agent.
[0008] A catalyst, such as a Ziegler-Natta catalyst, is usually
used for polymerization of olefin during manufacture of polyolefin
such as polypropylene, polyethylene, and the like. Residuals of
catalyst, such as chlorine compounds, remain in generated polymer.
The catalyst still remaining in polymer has a potential risk of
corroding or degrading polymer such as yellowing of polymer. For
this reason, a counteragent has been known to be added to the
resultant polymer so as to react with the residual catalyst to thus
neutralize the residual catalyst. Metallic salt of fatty acid, such
as calcium stearate, or hydrotalcite (basic aluminum magnesium
carbonate) has been known to be added as a counteragent.
[0009] Metallic salt of fatty acid, such as calcium stearate, is
commonly added in an amount of 1,000 to 1,500 ppm to polymer as a
counteragent for polypropylene. Using the metallic salt as the
ink-wetted member has been known to generate fibrous suspended
matters which in some cases will hinder flowability of ink. In
order to prevent generation of fibrous suspended matters,
JP-A-63-216752 proposes a method for reducing the amount of fatty
acid, such as calcium stearate, to 100 ppm or less.
[0010] Japanese Patent No. 2696828 describes a method for solving a
problem of suspended matters being formed by a solute originating
from the ink-wetted member by means of a combination of the density
of sodium ions in ink with the ink-wetted member. This method is
found to be insufficient in terms of accuracy of ejection of ink
achieved after the ink left for a long period of time has been
brought into contact with the ink-wetted member.
[0011] In recent years, employing ink which uses a pigment as an
ink coloring material for inkjet purpose has been energetically
discussed. Transforming a pigment into minute particles has been
proposed as a technique for realizing a pigment which enhances
print quality, an ejection characteristic, storage stability, a
clogging characteristic, a fixing characteristic, rubfastness, and
an increase in print speed, all of which are drawbacks in pigment
ink for inkjet use. For instance, JP-A-2003-3095 proposes that a
mean particle size of a pigment preferably ranges from 50 to 100
nm. However, this technique is not preferable in terms of
inconsistencies in density and inconsistent streaks, and a further
improvement in technique is sought.
SUMMARY OF THE INVENTION
[0012] The objective of the present invention is to enhance the
accuracy of ejection of ink achieved after ink has been brought in
contact with an ink-wetted member (when a principal component of
the member is polyolefins) such as an ink tank, an inkjet
cartridge, and/or an ink absorber for a long period of time.
Specifically, when variations in the volume of ejected ink have
become great and displacement from a target point of impact has
become large, inconsistencies in density and streaks are induced.
Accordingly, the objective of the present invention is to improve
the quality of inkjet printing.
[0013] The researchers of the present invention have attempted to
transform a pigment into minute particles by means of reducing a
volumetric mean particle size of the pigment to 110 nm, 70 nm, and
40 nm, and brought ink into contact with the ink-wetted member for
a long period of time, thereby improving the accuracy of ejection
of ink. A mere reduction in the volumetric mean particle size of a
pigment has ended in a failure to solve the problem. However, it
was found that the problem could be solved by a combination of a
specific ink-wetted member with specific ink.
[0014] The objectives of the present invention are achieved by the
following means.
[0015] [1] An ink unit comprising:
[0016] an ink utilized for an inkjet recorder; and
[0017] a wetted member that contacts with the ink,
[0018] wherein the ink comprises a pigment dispersedly held in a
medium, and the pigment contains particles of 200 nm or larger in 2
percent by volume or less, and
[0019] wherein a principal component of the ink-wetted member is a
polyolefin produced by addition of a hydrotalcite compound
represented by formula (X):
[A.sub.1-xD).sub.x(OH).sub.2].sup.x+[E.sub.x/n.mH.sub.2O].sup.x-
Formula (X)
[0020] wherein A in Formula (X) represents a divalent metal;
[0021] D represents a trivalent metal;
[0022] E represents an n-valence anion;
[0023] "m" represents an integer; and
[0024] "x" ranges from 0<.times.0.5.
[0025] Reference symbol A preferably represents bivalent metal such
as Mg, Mn, Fe, Co, Ni, Cu, Zn, and the like; D preferably
represents trivalent metal such as Al, Fe, Cr, Co, In, and the
like; and E preferably represents n-valence anion such as OH, F,
Cl, Br, NO.sub.3, CO.sub.3, SO.sub.4, Fe (CN).sub.6, CH.sub.3COO,
and the like.
[0026] [2] An ink unit comprising:
[0027] an ink utilized for an inkjet recorder; and
[0028] a wetted member that contacts with the ink,
[0029] wherein the ink comprises a pigment dispersedly held in a
medium, and the pigment contains particles of 200 nm or larger in 2
percent by volume or less, and
[0030] wherein a principal component of the ink-wetted member is a
polyolefin produced by addition of at least one of a fatty acid and
a fatty acid derivative.
[0031] [3] An ink unit comprising:
[0032] an ink utilized for an inkjet recorder; and
[0033] a wetted member that contacts with the ink,
[0034] wherein the ink comprises a pigment dispersedly held in a
medium, and the pigment contains particles of 200 nm or larger in 2
percent by volume or less, and
[0035] wherein a principal component of the ink-wetted member is a
polyolefin produced by addition of a phenolic antioxidant.
[4] An ink unit comprising:
[0036] an ink utilized for an inkjet recorder; and
[0037] a wetted member that contacts with the ink,
[0038] wherein the ink comprises a pigment dispersedly held in a
medium, and the pigment contains particles of 200 nm or larger in 2
percent by volume or less, and
[0039] wherein a principal component of the ink-wetted member is a
polyolefin produced by addition of a benzylidenesorbitol.
[0040] [5] The ink unit as described in any of [1] to [4]
above,
[0041] wherein the pigment is one of CI Pigment Yellow-12, CI
Pigment Yellow-17, CI Pigment Yellow-55, CI Pigment Yellow-74, CI
Pigment Yellow-97, CI Pigment Yellow-120, CI Pigment Yellow-128, CI
Pigment Yellow-151, CI Pigment Yellow-155 and CI Pigment
Yellow-180.
[0042] [6] The ink unit as described in any of [1] to [4]
above,
[0043] wherein the pigment is one of CI Pigment Red-122, CI Pigment
Violet-19, CI Pigment Red-57:1, CI Pigment Red-146 and CI Pigment
Blue-15:3.
[0044] [7] The ink unit as described in any of [1] to [6]
above,
[0045] wherein the ink is an ink set comprising at least a black
ink, a cyan ink, a magenta ink and a yellow ink, and
[0046] wherein all of the black ink, the cyan ink, the magenta ink
and the yellow ink contain a pigment dispersedly held in a medium,
and the pigment contains particles of 200 nm or larger in 2 percent
by volume or less.
[0047] [8] The ink unit as described in any of [1] to [7]
above,
[0048] wherein the pigment contains particles of 200 nm or larger
in 1 percent by volume or less.
[0049] [9] The ink unit as described in any of [1] to [7]
above,
[0050] wherein the pigment contains particles of 200 nm or larger
in 0.5 percent by volume or less.
[0051] [10] The ink unit as described in any of [1] to [9]
above,
[0052] wherein the polyolefin is a polypropylene.
[0053] [11] The ink unit as described in any of [1] to [10]
above,
[0054] wherein the ink-wetted member is an ink-wetted member of at
least one of an ink tank and an ink cartridge.
[0055] [12] The ink unit as described in any of [1] to [10]
above,
[0056] wherein the ink-wetted member is an ink-wetted member of an
ink absorber.
[0057] [13] The ink unit as described in any of [1] to [10]
above,
[0058] wherein the ink-wetted member is an ink-wetted member of at
least one of a tube of an ink supply system, a common flow passage
of a head, a pressure chamber of a head and a nozzle of a head.
BRIEF DESCRIPTION OF THE DRAWINGS
[0059] FIG. 1 is an example of a preferred inkjet recorder of the
present invention; and
[0060] FIG. 2 is a view showing the structure of an ink cartridge
used in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0061] As a result of ardent studies conducted by the present
inventors in order to achieve the objects, it is found that a
reduction in variations in the volume of ejected ink and a decrease
in displacement from a target point of impact are achieved by means
of a combination of a specific ink-wetted member with specific ink
in connection with the evaluation of ejection of ink performed
after ink has been left in contact with the ink-wetted member used
in the inkjet recorder over a long period of time or after ink has
been brought into contact with the ink-wetted member at high
temperature. As a result of ink having been brought into contact
with the ink-wetted member for a long period of time, occurrence of
suspended matters in ink is not ascertained, and hence drawbacks
are not made noticeable by means of visual evaluation of ink.
Superiority or inferiority in accuracy of ejection is construed to
be a phenomenon attributable to presence/absence of precipitates on
a meniscus in the vicinity of ink ejection nozzles.
[0062] In order to achieve the objects, [1] is characterized in
that the principal component of the ink-wetted member is
polyolefins obtained by means of adding compounds of hydrotalcites
in connection with a wetted member which is to contact ink used for
an inkjet recorder, wherein the ink contains a pigment dispersedly
held in a medium; and particles of 200 nm or larger in the pigment
account for 2 percent by volume or less.
[0063] Further, [2] is characterized in that a principal component
of the ink-wetted member is a polyolefin produced by addition of a
fatty acid and/or fatty acid derivatives.
[0064] Further, [3] is characterized in that a principal component
of the ink-wetted member is polyolefin produced by addition of
phenolic antioxidant having an isocyanurate skeleton.
[0065] Moreover, [4] is characterized in that a principal component
of the ink-wetted member is a polyolefin produced by addition of
benzylidenesorbitols obtained by means of addition of
alkyl-substituted benzylidene sorbitol.
[0066] [5] is characterized in that the pigment is one of CI
Pigment Yellow-12, CI Pigment Yellow-17, CI Pigment Yellow-55, CI
Pigment Yellow-74, CI Pigment Yellow-97, CI Pigment Yellow-120, CI
Pigment Yellow-128, CI Pigment Yellow-151, CI Pigment Yellow-155,
and CI Pigment Yellow-180.
[0067] [6] is characterized in that the pigment is one of CI
Pigment Red-122, CI Pigment Violet-19, CI Pigment Red-57:1, CI
Pigment Red-146, and CI Pigment Blue-15:3.
[0068] [7] is characterized in that the ink is an ink set including
at least black ink, cyan ink, magenta ink, and yellow ink; and that
all of the black ink, the cyan ink, the magenta ink, and the yellow
ink contain a pigment dispersedly held in a medium, and particles
of 200 nm or larger in the pigment account for 2 percent by volume
or less.
[0069] [8] is characterized in that particles of 200 nm or larger
in the pigment account for one percent by volume or less.
[0070] [9] is characterized in that particles of 200 nm or larger
in the pigment account for 0.5 percent by volume or less.
[0071] A volumetric mean particle size of the pigment preferably
ranges from 30 to 150 nm, more preferably from 40 to 120 nm.
[0072] The ink-wetted member referred to herein signifies a member,
such as an ink tank, an ink cartridge, or an ink absorber, which
contacts ink. The principal component of the wetted member is a
polyolefin. However, the principal component of the ink-wetted
member of the present invention shows that polyolefins account for
50% or more (in surface area ratio, and preferably in a mass ratio
as well), preferably 70% or more, more preferably 95% or more, and
much more preferably 99% or more of the entire wetted portion of
the member. (In this specification, mass ratio is equal to weight
ratio.)
[0073] The term "ink unit" used herein represents an aggregate of
ink and an ink wetted member in an ink supply system (an ink tank,
a tube, an ink cartridge, and an ink absorber) and an ink-wetted
member in a head (a common flow passage, a pressure chamber, and a
nozzle).
[0074] Polyolefins in the present invention refer to a polymer of
olefin, and include polyethylene, polypropylene, polybutene,
polystyrene, and copolymers thereof. A preferred polymer (resin) is
formed from ethylene and/or propylene, or selected from
homo-polypropylene (homo-PP), ethylene-propylene-random copolymer
(random copolymer PP), and ethylene-propylene-block copolymer
(block copolymer PP).
[0075] Hydrotalcite compounds are added to polyolefins of the
present invention.
[0076] The hydrotalcite compounds are unstable ratio compounds
represented by the formula
[A.sub.1-xD.sub.x(OH).sub.2].sup.x+[E.sub.x/n.mH.sub.2O].sup.x- [A
in Formula represents a divalent metal such as Mg, Mn, Fe, Co, Ni,
Cu, Zn, and the like; D represents a trivalent metal such as Al,
Fe, Cr, Co, In, and the like; E represents an n-valence anion such
as OH, F, Cl, Br, NO.sub.3, CO.sub.3, SO.sub.4, Fe(CN).sub.6,
CH.sub.3COO, and the like; "m" represents an integer; and "x"
ranges from 0<x.ltoreq.0.5].
[0077] For instance, specific examples of hydrotalcite compounds
can be enumerated as:
Mg.sub.6Al.sub.2(OH).sub.16.CO.sub.3.4H.sub.2O
Mg.sub.4.5Al.sub.2(OH).sub.13.CO.sub.3.3.5H.sub.2O
Ca.sub.6Al.sub.2(OH).sub.16.CO.sub.3.4H.sub.2O
Zn.sub.6Al.sub.2(OH).sub.16.CO.sub.3.4H.sub.2O
Mg.sub.3ZnAl.sub.2(OH).sub.12.CO.sub.3.4H.sub.2O.
[0078] Compounds described in JP-A-6-100734, JP-A-6-256588,
JP-A-10-87907, JP-A-10-139941, and JP-A-2001-316530 can be used as
the hydrotalcite compounds employed in the present invention.
[0079] Particularly-preferred compounds are represented by a
formula Mg.sub.1-xAl.sub.x(OH).sub.2 (CO.sub.3).sub.x/2.mH.sub.2O
(0<x.ltoreq.0.5).
[0080] No particular limitations are imposed on the method for
adding hydrotalcite compounds into polyolefin resin, and a known
method can be adopted. For instance, there can be used a method for
subjecting resin powder or pellets and powder of an additive agent
to dry-blending or a method for producing a master batch containing
a high concentration of additive agent, and adding the master batch
to unadded resin. There can also be adopted a continuous
melt-kneading method for adding a predetermined amount of
hydrotalcite compound, mixing the mixture by use of a
commonly-known mixer such as a Henshel mixer, a V blender or
tumbler mixer, and further mixing the thus-mixed mixture by use of
a uniaxial kneader or a dual-axis kneader such as a dual-axis
kneader of meshed unidirectional rotary type, a dual-axis kneader
of meshed bi-directional rotary type, a dual-axis kneader of
unmeshed unidirectional rotary type, and a dual-axis kneader of
unmeshed bi-directional rotary type; or a batch melt-kneading
method of roller type, Banbury type, or the like. A processing
method for producing a molded article from a polyolefin resin
composition is not subjected to a specific limitation. Any ordinary
resin molding method, such as an extruding method, a calendering
method, an injection molding method, a blow molding method, an
inflation molding method, may also be used.
[0081] A preferred amount of hydrotalcite compound to be added
ranges from 10 ppm to 10,000 ppm and more preferably 100 ppm to
1,000 ppm with respect to polyolefins.
[0082] A fatty acid and/or fatty acid derivatives are added to
polyolefins of the present invention. Specific examples of fatty
acid include a stearic acid, a behenic acid, an oleic acid, and an
erucic acid. Specific examples of a fatty acid derivatives include
Ca salt, Al salt, Mg salt, and Zn salt of stearic amides;
octadecanamides; Ca salt, Al salt, Mg salt, and Zn salt of a
behenic acid; amide behenates; Ca salt, Al salt, Mg salt, and Zn
salt of an oleic acid; oleic amide; Ca salt, Al salt, Mg salt, and
Zn salt of an erucic acid; and amide erucate. In addition,
compounds described as an antiacid and a lubricant in
JP-A-2003-96246 can be used as the fatty acid and/or the fatty acid
derivatives.
[0083] No particular limitations are imposed on the method for
adding a fatty acid and/or fatty acid derivatives into polyolefin
resin, and a known method can be adopted. For instance, there can
be used a method for subjecting resin powder or pellets and powder
of an additive agent to dry-blending or a method for producing a
master batch containing a high concentration of additive agent and
adding the master batch to an unadded resin. There can also be
adopted a continuous melt-kneading method for adding a
predetermined amount of fatty acid and/or fatty acid derivatives,
mixing the mixture by use of a commonly-known mixer such as a
Henshel mixer, a V blender or tumbler mixer, and further mixing the
thus-mixed mixture by use of a uniaxial kneader or a dual-axis
kneader such as a dual-axis kneader of meshed unidirectional rotary
type, a dual-axis kneader of meshed bi-directional rotary type, a
dual-axis kneader of unmeshed unidirectional rotary type, and a
dual-axis kneader of unmeshed bi-directional rotary type; or a
batch melt-kneading method of roller type, Banbury type, or the
like. A processing method for producing a molded article from a
polyolefin resin composition is not subjected to a specific
limitation. Any of ordinary resin molding methods, such as an
extruding method, a calendering method, an injection molding
method, a blow molding method, and an inflation molding method, may
also be used.
[0084] A preferred amount of a fatty acid and/or fatty acid
derivatives to be added ranges from 10 ppm to 1,000 ppm, more
preferably 50 ppm to 500 ppm with respect to polyolefins.
[0085] A phenolic antioxidant is added to the polyolefins of the
present invention.
[0086] Specific examples of the phenolic antioxidant include, but
are not limited to, [0087]
tris(4-t-butyl-2,6-dimethyl-3-hydroxybenzyl)isocyanurate, [0088]
tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, [0089]
2,6-di-tert-butyl-4-methylphenol, [0090]
4-hydroxymethyl-2,6-ditertiarybutylphenol, [0091]
2,6-di-tert-butyl-4-ethylphenol, butylated hydroxyanisole,
n-octadecyl.3-(4-hydroxy-3,5-di-tert-butylphenyl)propionate, [0092]
di-stearyl.(4-hydroxy-3-methyl-5-tert-butyl)benzylmalonate, [0093]
propyl gallate, octyl gallate, dodecyl gallate, tocopherol, [0094]
2,2'-methylenebis(4-methyl-6-tert-butyl-phenol), [0095]
2,2'-methylenebis(4-ethyl-6-tert-butyl-phenol), [0096]
4,4'-methylenebis(2,6-di-tert-butyl-phenol), [0097]
4,4'-butylidene-bis(6-tert-butyl-m-cresol), [0098]
4,4'-thiobis(6-tert-butyl-m-cresol), styrenated phenol, [0099]
N,N'-hexamethylene-bis(3,5-di-tert-butyl-4-hydroxyhydrocin namide),
[0100] bis(3,5-di-tert-butyl-4-hydroxybenzylethylesterphosphonate)
calcium, [0101]
1,1,3-tris(2-methyl-4-hydroxy-5-tert-butyl-phenyl)butane, [0102]
1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benze-
ne, [0103]
tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy
methyl]methane, [0104]
1,6-hexanediol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)pr
opionate], 2,2'-methylenebis(4-methyl-6-cyclohexanephenol), [0105]
2,2'-methylenebis[6-(1-methylcyclohexyl)-p-cresol], [0106]
1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocy anuric
acid, [0107]
1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid,
triethylene [0108]
glycol-bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propio nate],
[0109]
2,2'-oxamide-bis[ethyl.3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate],
[0110]
6-(4-hydroxy-3,5-di-tert-butylanilino)-2,4-di-octyl-thio-1,3,5-tri-
azine, [0111]
bis[2-tert-butyl-4-methyl-6-(2-hydroxy-3-tert-butyl-5-meth
ylbenzyl)phenyl]terephthalate, [0112]
3,9-bis[2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dim-
ethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, or [0113]
3,9-bis[2-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]-1,1-dimethy-
l-ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, and the like.
[0114] Preferred examples of the phenolic antioxidant include
[0115] tris(4-t-butyl-2,6-dimethyl-3-hydroxybenzyl)isocyanurate,
[0116] tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, [0117]
2,6-di-tert-butyl-4-methylphenol, [0118]
n-octadecyl.3-(4-hydroxy-3,5-di-tert-butylphenyl)propionate, [0119]
tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy
methyl]methane, triethylene [0120]
glycol-bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate],
4,4'-butylidene-bis(6-tert-butyl-m-cresol), [0121]
4,4'-thiobis(6-tert-butyl-m-cresol), [0122]
1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid,
[0123] 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butyl-phenyl)butane,
[0124]
3,9-bis[2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dim-
ethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, and the like.
[0125] Compounds described in JP-A-5-25330, JP-A-5-214176,
JP-A-8-231779, JP-A-8-283473, JP-A-9-67474, JP-A-9-169875,
JP-A-11-255973, and JP-A-2001-172438 can be used as the phenolic
antioxidant employed in the present invention.
[0126] No particular limitations are imposed on the method for
adding the phenolic antioxidant into polyolefin resin, and a known
method can be adopted. For instance, there can be used a method for
subjecting resin powder or pellets and powder of an additive agent
to dry-blending or a method for producing a master batch containing
a high concentration of additive agent and adding the master batch
to an unadded resin. There can also be adopted a continuous
melt-kneading method for adding a predetermined amount of phenolic
antioxidant, mixing the mixture by use of a commonly-known mixer
such as a Henshel mixer, a V blender or tumbler mixer, and further
mixing the thus-mixed mixture by use of a uniaxial kneader or a
dual-axis kneader such as a dual-axis kneader of meshed
unidirectional rotary type, a dual-axis kneader of meshed
bi-directional rotary type, a dual-axis kneader of unmeshed
unidirectional rotary type, and a dual-axis kneader of unmeshed
bi-directional rotary type; or a batch melt-kneading method of
roller type, Banbury type, or the like. A processing method for
producing a molded article from a polyolefin resin composition is
not subjected to a specific limitation. Any of ordinary resin
molding methods, such as an extruding method, a calendering method,
an injection molding method, a blow molding method, or an inflation
molding method, may also be used.
[0127] A preferred amount of phenolic antioxidant to be added
ranges from 100 ppm to 1,000 ppm, more preferably 500 ppm to 5,000
ppm with respect to polyolefins.
[0128] Benzylidenesorbitols are added to polyolefins of the present
invention.
[0129] Specific examples of benzylidenesorbitols include [0130]
1,3:2,4-di-benzylidenesorbitol, [0131]
1,3:2,4-bis(p-methylbenzylidene)sorbitol, [0132]
1,3:2,4-bis(p-methylbenzylidene benzylidene)sorbitol, [0133]
1,3:2,4-bis(3,4-dimethylbenzylidene)sorbitol, [0134]
1,3:2,4-(2,4-dimethylbenzylidene, benzylidene)sorbitol, [0135]
1,3:2,4-(2,5-dimethylbenzylidene, benzylidene)sorbitol, [0136]
1,3:2,4-bis(p-ethylbenzylidene)sorbitol, [0137]
1,3:2,4-bis(p-propylbenzylidene)sorbitol, [0138]
1,3:2,4-bis(p-butylbenzylidene)sorbitol, [0139]
1,3:2,4-bis(p-ethoxybenzylidene)sorbitol, [0140]
1,3:2,4-bis(p-butoxybenzylidene)sorbitol, [0141]
1,3:2,4-bis(p-chlorobenzylidene)sorbitol, [0142]
1,3:2,4-bis(p-bromobenzylidene)sorbitol, and the like. [0143]
1,3:2,4-di-benzylidenesorbitol, [0144]
1,3:2,4-bis(p-methylbenzylidene)sorbitol, [0145]
1,3:2,4-bis(p-methylbenzylidene benzylidene)sorbitol, [0146]
1,3:2,4-bis(3,4-dimethylbenzylidene)sorbitol, [0147]
1,3:2,4-(2,4-dimethylbenzylidene, benzylidene)sorbitol, [0148]
1,3:2,4-(2,5-dimethylbenzylidene, benzylidene) sorbitol, and [0149]
1,3:2,4-bis(p-ethylbenzylidene)sorbitol can be mentioned as
especially-preferable examples of benzylidenesorbitols.
[0150] Compounds described in JP-A-7-102123, JP-A-7-173342,
JP-A-7-278362, JP-A-9-157452, JP-A-9-286787, JP-A-2001-26682,
JP-A-2001-240698, and JP-A-2003-96246 can be used as the
benzylidenesorbitols employed in the present invention.
[0151] No particular limitations are imposed on the method for
adding benzylidenesorbitols into polyolefin resin, and a known
method can be adopted. For instance, there can be used a method for
subjecting resin powder or pellets and powder of an additive agent
to dry-blending or a method for producing a master batch containing
a high concentration of additive agent and adding the master batch
to an unadded resin. There can also be adopted a continuous
melt-kneading method for adding a predetermined amount of
benzylidenesorbitols, mixing the mixture by use of a commonly-known
mixer such as a Henshel mixer, a V blender or tumbler mixer, and
further mixing the thus-mixed mixture by use of a uniaxial kneader
or a dual-axis kneader such as a dual-axis kneader of meshed
unidirectional rotary type, a dual-axis kneader of meshed
bi-directional rotary type, a dual-axis kneader of unmeshed
unidirectional rotary type, and a dual-axis kneader of unmeshed
bi-directional rotary type; or a batch melt-kneading method of
roller type, Banbury type, or the like. A processing method for
producing a molded article from a polyolefin resin composition is
not subjected to a specific limitation. Any of ordinary resin
molding methods, such as an extruding method, a calendering method,
an injection molding method, a blow molding method, or an inflation
molding method, may also be used.
[0152] A preferred amount of sorbitol derivatives to be added
ranges from 100 ppm to 10,000 ppm, more preferably 500 ppm to 5,000
ppm, with respect to polyolefins.
[0153] As mentioned above, the characteristic of the present
invention lies in the fact that particles of 200 nm or larger in
the pigment account for 2 percent by volume or less. Although
particle sizes employed in the present invention can be measured by
an ordinary method, the sizes can also be measured by use of, e.g.,
Particle Size Analyzer UPA150 (NIKKISO Co., Ltd.).
[0154] As described on page 518 of Encyclopedic Dictionary of
Chemistry, Third Edition, Apr. 1, 1994 (edited by Michinori OKI, et
al.), the term "pigment" is a generic designation of coloring
matters which hardly dissolve in water or an organic solvent (white
matters are included in the case of an inorganic pigment), and
comprises organic pigments and inorganic pigments.
[0155] The "pigment dispersedly held in a medium" is used in the
present invention. However, the medium may contain a dispersing
agent or may not contain the same. Lipophilic mediums or aqueous
mediums may be used as a medium, but the aqueous mediums are
preferable.
[0156] A self-dispersing pigment can be mentioned as a pigment
preferably used in the present invention. The self-dispersing
pigment is formed by means of bonding a plurality of hydrophilic
groups and/or salts thereof (hereinafter called "dispersive
property imparting groups") directly to the surface of the pigment
or indirectly to the same by way of an alkyl group, an alkyl ether
group, an aryl group, and the like. The self-dispersing pigment can
be dispersed and/or dissolved in an aqueous medium without use of a
dispersing agent. Now, the expression "dispersed and/or dissolved
in an aqueous medium without use of a dispersing agent" signifies a
state where a pigment can be dispersed in an aqueous medium even
when a dispersing agent used for dispersing a pigment is not
used.
[0157] Ink containing the self-dispersing pigment as a coloring
agent does not need to contain a dispersing agent which is
contained in order to disperse an ordinary pigment, such as that
mentioned above. Foaming, which would otherwise be caused by a
deterioration in a defoaming characteristic induced by the
dispersing agent, hardly arises, and ink exhibiting superior
ejection stability is easy to prepare.
[0158] --COOH, --CO, --OH, --SO.sub.3H, PO.sub.3H.sub.2, quaternary
ammonium, and salts thereof can be mentioned as the
dispersive-property-imparting groups bonded to the surface of the
self-dispersing pigment. These dispersive property imparting groups
are manufactured by means of subjecting a pigment, which is to
become a raw material, to physical treatment or chemical treatment,
thereby bonding (grafting) the dispersive-property-imparting group
or an active species having the dispersive-property-imparting group
to the surface of the pigment. For instance, vacuum plasma
treatment, and the like, can be mentioned as physical treatment.
Further, a wet oxidation method for oxidizing the surface of a
pigment in water by means of an oxidant, a method for bonding a
carboxyl group by way of a phenyl group by means of bonding a
p-amino benzoic acid to the surface of the pigment, and the like
can be mentioned as chemical treatment.
[0159] In the present invention, a self-dispersing pigment--which
is subjected to surface treatment through oxidation treatment using
a hypohalous acid and/or a hypohalite or oxidation treatment using
ozone is preferable in terms of a high degree of coloring.
[0160] Commercial products can also be utilized as the
self-dispersing pigment. Microjet CW-1 (trade name: Orient Chemical
Industries Ltd.), CAB-O-JET200, CAB-O-JET300 (trade names: CABOT
Corporation), and the like, can be mentioned.
[0161] The self-dispersing pigment is contained, preferably within
a range from 2 to 20 mass percent, in the ink of the present
invention.
[0162] Micro-encapsulated pigments can be mentioned as the pigment
preferably used in the present invention. The micro-encapsulated
pigments are pigments coated with resin.
[0163] Resin of the micro-encapsulated pigments is not limited.
However, preferable resin exhibits self-dispersing capability or
dissolution capability with respect to water, and is a
macromolecular compound having an (acidic) anionic group.
Preferable resin usually has a number-average molecular weight of
about 1,000 to 100,000, and particularly preferable resin has a
number-average molecular weight of about 3,000 to 50,000. The resin
is preferably dissolved in an organic solvent to thus produce a
solution. As a result of the number-average molecular weight of
resin falling within the range, resin can sufficiently exhibit the
function of a coating film with respect to a pigment or the
function of a coating film in an ink composition.
[0164] Resin itself may has self-dispersing capability or
dissolving capability, or may also be given an analogous function
by means of additional introduction. For instance, an anionic
group, such as a carboxyl group, a sulfonic group, or a phosphonic
acid group, may be introduced into resin, by means of neutralizing
resin by use of, e.g., organic amine, alkaline metal, or the like.
One or two anionic groups of the same type or different types may
be introduced into resin. In the present invention, resin which is
neutralized by a base and provided with introduction of a carboxyl
group is preferably used.
[0165] As mentioned above, in the present invention, using resin in
the form of a salt of alkaline metal or a salt of organic amine is
preferable. When resin has been used in the form of a salt, ink
exhibiting a superior re-dispersive characteristic and superior
reliability can be provided. Specific example salts formed from
resin and alkaline metal include a lithium salt, a sodium salt, and
a potassium salt; preferably salts of alkaline metal such as a salt
of sodium hydroxide, a salt of potassium hydroxide, and a salt of
lithium hydroxide; more preferably a salt of potassium hydroxide.
Specific examples of salts of organic amine contained in resin
include salts of volatile amine compounds such as ammonia,
triethylamine, tributylamine, dimethylethanolamine,
diisopropanolamine, and morpholine; and salts of high-boiling
organic amine which are less likely to volatilize such as
diethanolamine, triethanolamine, and the like.
[0166] Specific examples of resin of an micro-encapsulated pigment
include polyvinyl-based materials such as vinyl chloride, vinyl
acetate, polyvinyl alcohol, polyvinyl butyral, and the like;
polyester-based materials such as alkyd resin, phthalic acid resin,
and the like; amino-based materials such as melamine resin,
melamine formaldehyde resin, aminoalkyd cocondensed resin, urea
resin, urea-formaldehyde resin, and the like; a material having an
anionic group such as thermoplastic, thermosetting, or degenerated
acrylic high molecular compounds, thermoplastic, thermosetting, or
degenerated epoxy-based high molecular compounds, thermoplastic,
thermosetting, or degenerated polyurethane-based high molecular
compounds, thermoplastic, thermosetting, or degenerated
polyether-based high molecular compounds, thermoplastic,
thermosetting, or degenerated polyamide-based high molecular
compounds, thermoplastic, thermosetting, or degenerated
unsaturated-polyester-based high molecular compounds,
thermoplastic, thermosetting, or degenerated phenolic high
molecular compounds, thermoplastic, thermosetting, or degenerated
silicon-based high molecular compounds, thermoplastic,
thermosetting, or degenerated fluorine-based high molecular
compounds, and copolymers or mixtures thereof.
[0167] Resin of the micro-encapsulated pigment may be formed by
previously making a glycidyl group, an isocyanate group, a hydroxyl
group, or a reactive active group such as .alpha.,.beta.-ethylene
unsaturated double bond (a vinyl group) pendant on resin, or mixing
with resin a cross-linking agent having a reactive active group;
e.g., melamine resin, urethane resin, epoxy resin, a photo-curing
agent such as ethylene unsaturated monomer or oligomer, or the
like. Resin having undergone such treatment yields advantages of
the ability to further enhance characteristics of a coating wall of
a pigment, such as solvent resistance, durability, or the like, and
the ability to enhance the strength of a film after a coating film
has been formed on a recording medium by ink.
[0168] Among the above-mentioned resins, anionic, acrylic resin is
obtained by means of polymerizing monomers in a solvent; e.g.,
acrylic monomer having an anionic group (hereinafter called
"anionic-group-containing acrylic monomer" and another monomer
capable of copolymerizing with the monomer, as needed. For
instance, acrylic monomer having one or more anionic groups
selected from the group consisting of a carboxyl group, a sulfonic
group, and a phosphonic group, is mentioned as
anionic-group-containing acrylic monomer. Of these monomers,
acrylic monomer having a carboxyl group is particularly
preferable.
[0169] Specific examples of acrylic monomer having a carboxyl group
include an acrylic acid, a methacrylic acid, a crotonic acid, an
ethacrylic acid, a propyl acrylic acid, an isopropyl acrylic acid,
an itaconic acid, a fumaric acid, and the like. Of these acids, an
acrylic acid or a methacrylic acid is preferable. Specific examples
of acrylic monomer having a sulfonic group include
sulfoethyl-methacrylate, a butyl-acrylic-amide-sulfonic acid, and
the like. Specific examples of acrylic monomer having a phosphonic
group include phosphoethylmethacrylate, and the like.
[0170] Specific examples of other monomers capable of
copolymerizing with anionic-group-containing acrylic monomer
include (meta) ester acrylate such as methyl acrylate, ethyl
acrylate, isopropyl acrylate, acrylate-n-propyl, acrylate-n-butyl,
acrylate-t-butyl, acrylate-2-ethylhexyl, acrylate-n-octyl, lauryl
acrylate, benzyl acrylate, methyl methacrylate, ethyl methacrylate,
isopropyl methacrylate, methacrylate-n-propyl,
methacrylate-n-butyl, isobutyl methacrylate, methacrylate-t-butyl,
methacrylate-2-ethylhexyl, methacrylate-n-octyl, lauryl
methacrylate, stearyl methacrylate, tridecyl methacrylate, benzyl
methacrylate, and the like; an additional reactant formed from oil
fatty acid and (meta) acrylic ester monomer having an oxirane, such
as an additional reactant formed from a stearic acid and glycidyl
methacrylate; an additional reactant formed from an oxirane
compound including an alkyl group having three carbon atoms or more
and a (meta) acrylic acid; a styrene-based monomer such as styrene,
.alpha.-methylstyrene, o-methylstyrene, m-methylstyrene,
p-methylstyrene, p-tert-butylstyrene, and the like; itaconate ester
such as itaconic benzyl, and the like; maleate ester such as
dimethyl maleate, and the like; fumaric ester such as fumaric
diethyl fumarate and the like; acrylonitrile, methacrylonitrile,
vinyl acetate, isobornyl acrylate, isobornyl methacrylate,
aminoethyl acrylate, aminopropyl acrylate, methylaminoethyl
acrylate, methylaminopropyl acrylate, ethylaminoethyl acrylate,
ethylaminopropyl acrylate, aminoethylamide acrylate,
aminopropylamide acrylate, methylaminoethylamide acrylate,
methylaminopropylamide acrylate, ethylaminoethylamide acrylate,
ethylaminopropylamide acrylate, amide methacrylate, aminoethyl
methacrylate, aminopropyl methacrylate, methylaminoethyl
methacrylate, methylaminopropyl methacrylate, ethylaminoethyl
methacrylate, ethylaminopropyl methacrylate, aminoethylamide
methacrylate, aminopropylamide methacrylate, methylaminoethylamide
methacrylate, methylaminopropylamide methacrylate,
ethylaminoethylamide methacrylate, ethylaminopropylamide
methacrylate, hydroxymethyl acrylate, acrylate-2-hydroxyethyl,
acrylate-2-hydroxypropyl, hydroxymethyl methacrylate,
methacrylate-2-hydroxyethyl, methacrylate-2-hydroxypropyl,
N-methylolacrylamide, allyl alcohol, and the like.
[0171] Examples of monomers having a cross-linking functional group
are as follows. Polymeric monomers having a blocked isocyanate
group can be readily manufactured by means of causing a known
blocking agent to additionally react with a polymeric monomer
having an isocyanate group such as
2-methacryloyloxymethylisocyanate. Alternatively, polymeric
monomers having a blocked isocyanate group can be readily
manufactured by means of causing a compound having an isocyanate
group and a blocked isocyanate group to additionally react with the
above-mentioned vinyl-based copolymer having a hydroxyl group and a
carboxyl group. A compound having an isocyanate group and a blocked
isocyanate group can be readily obtained by means of causing a
di-isocyanate compound to additionally react with a known blocking
agent at a mole ratio of about 1:1.
[0172] Examples of a monomer having an epoxy group include glycidyl
(meta) acrylate, a (meta) acrylate monomer having an alicyclic
epoxy group, and the like. Examples of a monomer having a
1,3-dioxolane-2-on-4-yl group include [0173]
1,3-dioxolane-2-on-4-ylmethyl (meta) acrylate, [0174]
1,3-dioxolane-2-on-4-ylmethylvinylether, and the like.
[0175] Examples of a polymerization initiator include a peroxide
such as t-butyl-peroxybenzoate, di-t-butylperoxide,
cumeneperhydrooxide, acetylperoxide, benzoylperoxide,
lauroylperoxide, and the like; and an azo-compound such as
azobisisobutyronitrile, azobis-2,4-dimethylvaleronitrile,
azobiscyclohexanecarbonitrile, and the like.
[0176] Examples of a solvent used when an anionic-group-containing
acrylic monomer is copolymerized with another monomer capable of
copolymerizing with the monomer, as needed, include an aliphatic
hydrocarbons solvent such as hexane, mineral spirits, and the like;
an aromatic hydrocarbons solvent, such as benzene, toluene, xylene,
and the like; an ester solvent such as butyl acetate; a ketone
solvent such as methyl ethyl ketone, isobutylmethyl ketone, and the
like; an alcohol solvent such as methanol, ethanol, butanol,
isopropyl alcohol, and the like; and an aprotic polar solvent such
as dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone,
pyridine, and the like. Two or more types of the solvents can also
be used in combination.
[0177] Preferably, in the present invention, resin coating a
pigment further contains a curing agent and/or a high molecular
compound. More preferably, the pigment is further coated with a
curing agent and/or a high molecular compound. The curing agent or
the high molecular compound acts so as to cure a coating film of a
coloring agent or enhance the strength of a coating film when the
curing agent or the high molecular compound is used in ink.
[0178] Specific examples of a curing agent employed in the present
invention comprise amino resin such as melamine resin,
benzoguanamine resin, urea resin, and the like; phenolic resin such
as trimethylolphenol, condensates thereof, and the like;
polyisocyanate such as tetramethylene-diisocyanate (TDI),
hexamethylene-di-isocyanate (HDI), diphenylmethane-diisocyanate
(MDI), naphthalene-diisocyanate (NDI), isophorone-diisocyanate
(IPDI), xylene-diisocyanate (XDI), transformed isocyanate thereof
or blocked isocyanate thereof, and the like; amines such as
aliphatic amine, aromatic amine, N-methylpiperazine,
triethanolamine, morpholine, dialkylamino ethanol,
benzyldimethylamine, and the like; acid anhydrides such as a
polycarboxylic acid, phthalic anhydride, maleic anhydride,
hexahydrophthalic anhydride, pyromellitic dianhydride,
benzophenonetetracarboxylic anhydride,
ethyleneglycolbis-trimellitate, and the like; epoxy compounds such
as bisphenol-A epoxy resin, phenolic epoxy resin, glycidyl
methacrylate copolymer, glycidyl ester resin of carboxylic acid,
alicyclic epoxy, and the like; alcohols such as polyetherpolyol,
polybutadiene glycol, polycaprolactonepolyol,
trishydroxyethylisocyanate (THEIC), and the like; and vinyl
compounds such as a polyvinyl compound serving as an
unsaturated-group-containing compound used for radical curing, UV
curing, or electron curing induced by peroxide, a polyallyl
compound, a reactant formed from glycol, polyol, an acrylic acid, a
methacrylic acid, or the like.
[0179] More preferably, an attempt is made to accelerate curing by
means of addition of a photoinitiator, a polymerization initiator,
or a catalyst. Examples of the photoinitiator include benzoins,
anthraquinones, benzophenones, a sulfur-containing compound,
dimethylbenzylketal, and the like. However, the photoinitiator is
not limited to them. Examples of the polymerization initiator
include peroxides such as t-butylperoxidebenzoate,
di-t-butylperoxide, cumeneperhydroxide, acetylperoxide,
benzoylperoxide, lauroylperoxide, and the like; and an azo-compound
such as azobisisobutyronitrile, azobis-2,4-dimethylvaleronitrile,
azobiscyclohexanecarbonitrile, and the like. examples of the
catalyst include Co compounds, Pb compounds, and the like.
[0180] In relation to high molecular compounds that can be used in
the present invention, any high molecular compound can be used
without particular limitations, so long as the compound has a
number-average molecular weight of 1,000 or more. A number-average
molecular weight preferably ranges from 3,000 to 100,000 in terms
of the strength of an ink film and manufacture of a pigment coating
film.
[0181] No specific limitations are imposed on the type of high
molecular compounds. Examples of the high molecular compounds
include polyvinyl-based materials such as vinyl chloride, vinyl
acetate, polyvinyl alcohol, polyvinyl butyral, and the like;
polyester-based materials such as alkyd resin, phthalic acid resin,
and the like; amino-based materials such as melamine resin,
melamine formaldehyde resin, aminoalkyd cocondensed resin, urea
resin, urea-formaldehyde resin, and the like; and high molecular
compounds including thermoplastic, thermosetting, or degenerated
acrylic high molecular compounds, thermoplastic, thermosetting, or
degenerated epoxy-based high molecular compounds, thermoplastic,
thermosetting, or degenerated polyurethane-based high molecular
compounds, thermoplastic, thermosetting, or degenerated
polyether-based high molecular compounds, thermoplastic,
thermosetting, or degenerated polyamide-based high molecular
compounds, thermoplastic, thermosetting, or degenerated
unsaturated-polyester-based high molecular compounds,
thermoplastic, thermosetting, or degenerated phenolic high
molecular compounds, thermoplastic, thermosetting, or degenerated
silicon-based high molecular compounds, thermoplastic,
thermosetting, or degenerated fluorine-based high molecular
compounds, and copolymers or mixtures thereof.
[0182] Manufacture of a Micro-Encapsulated Pigment
[0183] A micro-encapsulated pigment can be manufactured by use of
the above-mentioned components and by means of a conventional
physical method or a conventional chemical method. According to a
preferred mode of the present invention, the micro-encapsulated
pigment can be manufactured by means of the methods described in
JP-A-9-151342, JP-A-10-140065, JP-A-11-209672, JP-A-11-172180,
JP-A-10-25440, and JP-A-11-43636. Manufacturing methods described
in these publications are briefly described hereunder.
[0184] A "phase inversion method" and an "acid analysis method" are
described in JP-A-9-1513142 and JP-A-10-140065.
[0185] a) "Phase Inversion Method"
[0186] In the present invention, a "phase inversion method"
basically refers to a self-dispersion (phase inversion
emulsification) method which disperses into water a mixed melt
substance consisting of a pigment and resin having self-dispersing
capability or dissolution capability. Alternatively, a mixed melt
substance may contain the curing agent or the high molecular
compound. The term "mixed melt substance" means a substance in a
mixed-but-undissolved state, a substance in a dissolved-and-mixed
state, a substance in a mixed-but-undissolved state, and a
substance in a dissolved-and-mixed state.
[0187] b) "Acid Analysis Method"
[0188] In the present invention, the "acid analysis method" refers
to a method for manufacturing a micro-encapsulated pigment by means
of preparing a hydrated cake from resin and a pigment, and
neutralizing some or all of anionic groups contained in resin of
the hydrated cake, by use of a basic compound.
[0189] The "acid analysis method" specifically comprises (1) a step
of making an attempt to gel resin by means of dispersing resin and
a pigment into an alkaline aqueous medium and subjecting the liquid
mixture to heating treatment, as required; (2) a step of rendering
a pH level of the gel neutral or acidic, to thus make resin
hydrophobic and cause the resin to intensively adhere to the
pigment; (3) a step of subjecting the pigment to filtering and
cleansing as required, to thus produce a hydrated cake; (4) a step
of neutralizing some or all of anionic groups contained in resin of
the hydrated cake, by use of a basic compound, and re-dispersing
the cake into an aqueous medium; and (5) a step of subjecting the
liquid mixture to heating treatment as required, to thus make an
attempt to gel resin. More specific manufacturing methods of the
"Phase Inversion Method" and the "Acid Analysis Method" may be
analogous to those described in JP-A-9-151342 and
JP-A-10-140065.
[0190] A method for manufacturing a coloring agent is described in
JP-A-11-209672 and JP-A-11-172180. The general features of the
manufacturing method are basically formed from manufacturing steps
provided below.
[0191] Namely, the manufacturing steps comprise (1) a step of
mixing a basic compound with resin having anionic groups or a
solution prepared by dissolving the resin in an organic solvent, to
thus neutralize the mixture; (2) a step of mixing a pigment with
the liquid mixture and suspending the liquid mixture, and
subsequently dispersing the pigment by means of a disperser or the
like, to thus obtain a pigment-dispersed liquid; (3) distilling a
solvent as required to thus remove the solvent; (4) a step of
adding an acidic compound to the mixture to thus deposit resin
having anionic groups, thereby coating the pigment with the resin
having anionic groups; (5) a step of subjecting the pigment to
filtering and cleansing as required; and (6) a step of adding a
basic compound to the mixture to thus neutralize the anionic groups
of resin having the anionic groups and to thereby disperse the
resin into an aqueous medium and generate an aqueous dispersoid. A
more specific manufacturing method may be analogous to that
described in JP-A-11-2096722 and JP-A-11-172180.
[0192] In relation to pigments usable in the present invention,
examples of a pigment for yellow ink include CI Pigment Yellow-1,
CI Pigment Yellow-2, CI Pigment Yellow-3, CI Pigment Yellow-4, CI
Pigment Yellow-5, CI Pigment Yellow-6, CI Pigment Yellow-7, CI
Pigment Yellow-10, CI Pigment Yellow-11, CI Pigment Yellow-12, CI
Pigment Yellow-13, CI Pigment Yellow-14, CI Pigment Yellow-14C, CI
Pigment Yellow-16, CI Pigment Yellow-17, CI Pigment Yellow-24, CI
Pigment Yellow-34, CI Pigment Yellow-35, CI Pigment Yellow-37, CI
Pigment Yellow-42, CI Pigment Yellow-53, CI Pigment Yellow-55, CI
Pigment Yellow-65, CI Pigment Yellow-73, CI Pigment Yellow-74, CI
Pigment Yellow-75, CI Pigment Yellow-81, CI Pigment Yellow-83, CI
Pigment Yellow-93, CI Pigment Yellow-95, CI Pigment Yellow-97, CI
Pigment Yellow-98, CI Pigment Yellow-100, CI Pigment Yellow-101, CI
Pigment Yellow-104, CI Pigment Yellow-108, CI Pigment Yellow-109,
CI Pigment Yellow-110, CI Pigment Yellow-114, CI Pigment
Yellow-117, CI Pigment Yellow-120, CI Pigment Yellow-128, CI
Pigment Yellow-129, CI Pigment Yellow-138, CI Pigment Yellow-150,
CI Pigment Yellow-151, CI Pigment Yellow-153, CI Pigment
Yellow-154, CI Pigment Yellow-155, and CI Pigment Yellow-180.
[0193] Examples of a pigment for magenta ink include CI Pigment
Red-1, CI Pigment Red-2, CI Pigment Red-3, CI Pigment Red-4, CI
Pigment Red-5, CI Pigment Red-6, CI Pigment Red-7, CI Pigment
Red-8, CI Pigment Red-9, CI Pigment Red-10, CI Pigment Red-11, CI
Pigment Red-12, CI Pigment Red-13, CI Pigment Red-14, CI Pigment
Red-15, CI Pigment Red-16, CI Pigment Red-17, CI Pigment Red-18, CI
Pigment Red-19, CI Pigment Red-21, CI Pigment Red-22, CI Pigment
Red-23, CI Pigment Red-30, CI Pigment Red-31, CI Pigment Red-32, CI
Pigment Red-37, CI Pigment Red-38, CI Pigment Red-39, CI Pigment
Red-40, CI Pigment Red-48 (Ca), CI Pigment Red-48 (Mn), CI Pigment
Red-48:2, CI Pigment Red-48:3, CI Pigment Red-48:4, CI Pigment
Red-49, CI Pigment Red-49:1, CI Pigment Red-50, CI Pigment Red-51,
CI Pigment Red-52, CI Pigment Red-52:2, CI Pigment Red-53:1, CI
Pigment Red-53, CI Pigment Red-55, CI Pigment Red-57 (Ca), CI
Pigment Red-57:1, CI Pigment Red-60, CI Pigment Red-60:1, CI
Pigment Red-63:1, CI Pigment Red-63:2, CI Pigment Red-64, CI
Pigment Red-64:1, CI Pigment Red-81, CI Pigment Red-83, CI Pigment
Red-87, CI Pigment Red-88, CI Pigment Red-89, CI Pigment Red-90, CI
Pigment Red-101 (iron oxide red), CI Pigment Red-104, CI Pigment
Red-105, CI Pigment Red-106, CI Pigment Red-108 (cadmium red), CI
Pigment Red-112, CI Pigment Red-114, CI Pigment Red-122
(Quinacridone magenta), CI Pigment Red-123, CI Pigment Red-146, CI
Pigment Red-149, CI Pigment Red-163, CI Pigment Red-166, CI Pigment
Red-168, CI Pigment Red-170, CI Pigment Red-172, CI Pigment
Red-177, CI Pigment Red-178, CI Pigment Red-179, CI Pigment
Red-184, CI Pigment Red-185, CI Pigment Red-190, CI Pigment
Red-193, CI Pigment Red-202, CI Pigment Red-209, CI Pigment
Red-219, and the like. Particularly, CI Pigment Red-122 is
preferable.
[0194] Examples of a pigment for cyan ink include CI Pigment
Blue-1, CI Pigment Blue-2, CI Pigment Blue-3, CI Pigment Blue-15,
CI Pigment Blue-15:1, CI Pigment Blue-15:2, CI Pigment Blue-15:3,
CI Pigment Blue-15:34, CI Pigment Blue-16, CI Pigment Blue-17:1, CI
Pigment Blue-22, CI Pigment Blue-25, CI Pigment Blue-56, CI Pigment
Blue-60, CI Vat Blue-4, CI Vat Blue-60, and CI Vat Blue-63.
Particularly, CI Pigment Blue-15:3 is preferable.
[0195] Examples of pigments for other colors of ink include CI
Pigment Orange-5, CI Pigment Orange-13, CI Pigment Orange-16, CI
Pigment Orange-17, CI Pigment Orange-36, CI Pigment Orange-43, CI
Pigment Orange-51; CI Pigment Green-1, CI Pigment Green-4, CI
Pigment Green-7, CI Pigment Green-8, CI Pigment Green-10, CI
Pigment Green-17, CI Pigment Green-18, CI Pigment Green-36; CI
Pigment Violet-1 (RHODAMINE Lake), CI Pigment Violet-3, CI Pigment
Violet-5:1, CI Pigment Violet-16, CI Pigment Violet-19
(Quinacridone red), CI Pigment Violet-23, CI Pigment Violet-38, and
the like. In addition, a processed pigment, such as graft carbon
produced by processing the surface of a pigment with resin, can
also be employed.
[0196] For example, carbon black can be mentioned as a black color
pigment. Specific examples of carbon black include No. 2300, No.
900, MCF88, No. 33, No. 40, No. 45, No. 52, MA7, MA8, MA100, and
No. 2200B, and the like, all of which are manufactured by
Mitsubishi Chemical Corporation; Raven 5750, Raven 5250, Raven
5000, Raven 3500, Raven 1255, Raven 700, and the like, all of which
are manufactured by Columbian Chemicals Company; Regal 400R, Regal
330R, Regal 660R, Mogul L, Monarch 700, Monarchy 800, Monarch 880,
Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, Monarch
1400, and the like, all of which are manufactured by CABOT
Corporation; and Color Black FW1, Color Black FW2, Color Black
FW2V, Color Black FW18, Color Black FW200, Color Black 5150, Color
Black 5160, Color Black S170, Printex 35, Printex U, Printex V,
Printex 140U, Special Black 6, Special Black 5, Special Black 4A,
Special Black 4, and the like, all of which are manufactured by
Degussa Corporation.
[0197] These pigments may be used in form of a single type, or a
plurality of pigments may be selected from one or more of the
groups and used in combination.
[0198] [Inkjet Recording Method]
[0199] According to the inkjet recording method of the present
invention, energy is supplied to ink for inkjet recording purpose,
to thus form an image on a known image-receiving material; namely,
plain paper or resin-coated paper; for instance, inkjet-only paper,
a film, electrophotographic common-use paper, cloth, glass, metal,
ceramics, and the like, described in JP-A-8-169172, JP-A-8-27693,
JP-A-2-276670, JP-A-7-276789, JP-A-9-323475, JP-A-62-238783,
JP-A-10-153989, JP-A-10-217473, JP-A-10-235995, JP-A-10-337947,
JP-10-217597, JP-A-10-337947, and the like. Descriptions ranging
from paragraph number 0093 to paragraph number 0105 in
JP-A-2003-306623 can be applied as the inkjet recording method of
the present invention.
[0200] During formation of an image, with a view toward imparting a
glossing characteristic and waterproofing to an image-receiving
material and enhancing weatherability of the same, a polymer latex
compound may also be used in combination. Timing when a latex
compound is imparted to an image-receiving material may be before
or after imparting of a coloring agent to the material, or a latex
compound may be imparted to the material simultaneously with the
coloring agent. Consequently, a latex compound may be added to an
image-receiving material or ink, or may be used in the form of a
liquefied substance consisting solely of polymer latex.
Specifically, methods described in JP-A-2002-166638 (Japanese
Patent Application No. 2000-363090), JP-A-2002-121440 (Japanese
Patent Application No. 2000-315231), JP-A-2002-154201 (Japanese
Patent Application No. 2000-354380), JP-A-2002-144696 (Japanese
Patent Application No. 2000-343944), and JP-A-2000-080759 (Japanese
Patent Application No. 2000-268952) can be preferably used.
[0201] Occurrence of a bronzing phenomenon can be prevented by
means of adding, to a dispersed pigment of the present invention, a
colorless aqueous plane compound having ten or more nonlocalized
.pi. electrons in one molecule. The bronzing phenomenon is a
phenomenon in which, in a case where a recorded image of high
optical density is formed, crystal of a pigment being deposited on
the surface of a recording material as an image becomes dry,
whereby the recorded image reflects light to thus exhibit metallic
luster. This phenomenon tends to easily arise when a water
solubility of a pigment is reduced or a hydrogen bonding group is
introduced into the structure of a pigment in order to enhance
waterproofing, radiationproofing, and gasproofing of an
image-receiving material.
[0202] Since light is reflected or scattered by means of occurrence
of a bronzing phenomenon, a great change in the hue of a recorded
image from a desired hue level and loss of transparency as well as
a decrease in optical density of a recorded image arise. For these
reasons, inhibition of occurrence of a bronzing phenomenon is an
important characteristic required of ink for inkjet purposes.
[0203] A colorless aqueous plane compound having ten or more
nonlocalized .pi. electrons in one molecule, which is preferably
used in the present invention, will now be described. In many
cases, the number of .pi. electrons constituting a nonlocalized
.pi. electron system increases, and absorption arises in a visible
range as the .pi. electron system expands. The term "colorless" of
the present invention includes a state where a compound is
minimally colored to such an extent that an image is not affected
by the color. The colorless aqueous plane compound may also be a
fluorescent compound. However, a nonfluorescent compound is
preferable; a compound whose .lamda.max of an absorption peak at
the lowest frequency side is 350 nm or less and whose mol
absorption coefficient is 10,000 or less is more preferable; and a
compound whose .lamda.max of an absorption peak at the lowest
frequency side is 320 nm or less and whose mol absorption
coefficient is 10,000 or less is particularly preferable.
[0204] The compound has ten or more nonlocalized .pi. electrons in
one molecule. Although no particular limitations are imposed on the
maximum number of .pi. electrons, 80 .pi. electrons or less are
preferable, 50 .pi. electrons or less are more preferable, and 30
.pi. electrons or less are particularly preferable. 10 .pi.
electrons or more may form one large nonlocalized system, or may
form two or more nonlocalized systems. Particularly, a compound
having two or more aromatic rings in one molecule is preferable.
The aromatic ring may be an aromatic hydrocarbon ring or an
aromatic heterocycle including hetero atoms, or a ring which is
subjected to annelation to thus form a single aromatic ring.
Examples of the aromatic ring include benzene, naphthalene,
anthracene, pyridine, pyrimidine, pyrazine, triazine, and the
like.
[0205] A compound which is dissolved in an amount of at least 1 g
or more in 100 g of water at 20.degree. C. is preferable as the
aqueous plane compound preferably employed in the present
invention. A compound which is dissolved in an amount of 5 g or
more in 100 g of water at 20.degree. C. is more preferable. A
compound which is dissolved in an amount of 10 g or more in 100 g
of water at 20.degree. C. is particularly preferable.
[0206] In the case of a compound having two or more aromatic rings
in one molecule, the compound particularly preferably has at least
two solubilization groups bonded to an aromatic ring in the
molecule. Examples of a useful solubilization group include a
sulfonic group, a carboxyl group, a hydroxy group, a phosphonic
group, a carbonamide group, a sulfonamide group, a quaternary
ammonium salt, and other groups which are obvious to the person
skilled in the art. However, the useful solubilization group is not
limited to the groups mentioned above. Of these groups, the
sulfonic group and the carboxyl group are preferable, and the
sulfonic group is most preferable.
[0207] The maximum number of solubilization groups in a molecule is
limited only by the number of locations of available substitutional
groups. For practical purposes, presence of 10 identical or
different solubilization groups in a molecule is sufficient. No
limitations are imposed on counter cations of these solubilization
groups. Alkaline metal, ammonium, and organic cations
(tetramethylammonium, guanidinium, pyridinium, and the like) can be
mentioned as counter cations. Of these counter cations, alkaline
metal and ammonium are preferable. Particularly, lithium, sodium,
potassium, and ammonium are preferable. Lithium, sodium, and
ammonium are most preferable.
[0208] Specific compounds include those described in JP-A-63-55544,
JP-A-3-146947, JP-A-3-149543, JP-A-2001-201831, JP-A-2002-139822,
JP-A-2002-196460, JP-A-2002-244257, JP-A-2002-244259,
JP-A-2002-296743, JP-A-2002-296744, JP-A-2003-255502,
JP-A-2003-307823, JP-A-2004-4500, JP-A-2004-170964, and
specifications thereof.
[0209] Compounds represented by formula VI provided below are
preferably used.
A-X-L-(Y--B).sub.n Formula VI
[0210] In the formula, A, L, B each independently represents
aromatic groups (an aryl group and an aromatic heterocyclic group),
respectively. X and Y each independently represents bivalent
bonding groups. In the formula, "n" represents 0 or 1. The aromatic
group may be a monocyclic ring or a condensed ring. The bivalent
bonding group includes an alkylene group, an alkenyne group,
--CO--, --SO.sub.n-- (n represents 0, 1, 2), --NR--(R represents a
hydrogen atom, an alkyl group, an aryl group, and a heterocyclic
group), --O--, and bivalent groups formed by combination of these
bonding groups. A compound represented by the formula VI contains
at least an ionic hydrophilic group selected from a sulfonic group,
a carboxyl group, a phenolic hydroxyl group, and a phosphonic
group. These ionic hydrophilic groups may assume the form of a
salt. No limitations are imposed on counter cations thereof.
Alkaline metal, ammonium, organic cations (tetramethylammonium,
guanidinium, pyridinium, and the like) can be mentioned as counter
cations. Of these counter cations, alkaline metal and ammonium are
preferable; lithium, sodium, potassium, and ammonium are
particularly preferable; and lithium, sodium, and ammonium are most
preferable.
[0211] The compound represented by the formula VI may have a
substitutional group other than an ionic hydrophilic group.
Specific substitutional groups include an alkyl group, an allyl
group, an aralkyl group, a heterocyclic group, an alkoxy group, an
alkoxyl group, an aryloxy group, a hydroxyl group, an amino group
(including an anilino group and a heterocyclic amino group), an
acyl group, an acylimino group, an ureido group, a halogen atom, a
sulfamoyl group, a carbamoyl group, a sulfonamide group, a
sulphonyl group, a sulfenyl group, a sulfinyl group, and the like.
These substitutional groups may additionally have another
substitutional group. Of the compounds represented by formula VI, a
compound acquired when n=1 is substituted into the formula is
preferable. Further, compounds acquired when at least one of A, L,
and B is an aromatic heterocycle are preferable. Moreover,
compounds containing two to four ionic hydrophilic groups are
preferable.
[0212] Typical compounds (deflocculation agents) are provided as
follows:
##STR00001## ##STR00002## ##STR00003##
[0213] Ink for inkjet purpose can be manufactured by means of
dissolving and/or dispersing a pigment into a lipophilic medium or
an aqueous medium. When an aqueous medium is used, another additive
is contained, as required, within a range where the advantage of
the present invention is not impaired.
[0214] Other additives include known additives; e.g., a desiccation
inhibitor (a wetting agent), a discoloration inhibitor, an emulsion
stabilizer, a permeation promoter, an ultraviolet absorber, an
antiseptic agent, an antifungal agent, a pH controlling agent, a
surface tension controlling agent, an antifoamer, a viscosity
modifier, a dispersing agent, a dispersion stabilizer, a
rust-preventive agent, a chelating agent, and the like. Additives
of these types are added directly to an ink fluid in the case of
water-soluble ink. When an oil-soluble dye is used in the form of a
dispersed substance, the dye is generally added to a dispersed
substance generated after preparation of a dye disperse substance.
However, the dye may also be added to an oil phase or a water phase
during preparation.
[0215] The desiccation inhibitor is preferably used for the purpose
of preventing occurrence of a clog, which would otherwise be caused
when the ink for inkjet purpose is desiccated at an ink ejection
nozzle used for an inkjet recording system. A water-soluble organic
solvent which is lower than water in terms of vapor pressure is
preferable as the desiccation inhibitor. Specific examples of the
desiccation inhibitor include polyhydric alcohols typified by
ethylene glycol, propylene glycol, diethylene glycol, polyethylene
glycol, thiodiglycol, dithiodiglycol, 2-methyl-1,3-propanediol,
1,2,6-hexanetriol, acetylenic glycol derivatives, glycerin,
trimethylolpropane, and the like; lower alkyl ethers of polyhydric
alcohols including [0216] ethylene glycol monomethyl (or
ethyl)ether, [0217] diethyleneglycolmonomethyl (or ethyl)ether,
[0218] triethyleneglycolmonoethyl (or butyl)ether, and the like;
[0219] heterocycles including 2-pyrolidone, N-methyl-2-pyrolidone,
1,3-dimethyl-2-imidazolidinone, N-ethylmorpholine, and the like;
sulfur-containing compounds including sulfolane, dimethylsulfoxide,
3-sulfolene, and the like; multifunctional compound including
diacetone alcohol, diethanolamine, and the like. Of these organic
solvents, polyhydric alcohols including glycerin, diethyleneglycol,
and the like; and ureas, are more preferable. The desiccation
inhibitor may be used alone, or two types of desiccation inhibitors
or more may be used in combination. These desiccation inhibitors
are preferably contained in ink in an amount of 10 to 50 mass
percent.
[0220] The permeation promoter is preferably used for the purpose
of causing inkjet ink to well permeate through paper. As the
permeation promoter, there can be used alcohols such as ethanol,
isopropanol, butanol, di(tri)ethyleneglycolmonobutylether,
1,2-hexanediol, and the like; as well as sodium lauryl sulfate,
sodium oleate, a nonionic surface active agent, and the like. When
the permeation promoter is contained in ink in an amount of 5 to 30
mass percent, a sufficient advantage is usually yielded.
Preferably, the permeation promoter is used in a range where
blotting of ink in printed letters or a print-through phenomenon is
not induced.
[0221] The ultraviolet absorber is used for the purpose of
enhancing the holding characteristics of an image. Examples of the
ultraviolet absorber include benzotriazole-based compounds
described in JP-A-58-185677, JP-A-61-190537, JP-A-2-782,
JP-A-5-197075, JP-A-9-34057, and like compounds; benzophenone-based
compounds described in JP-A-46-2784, JP-A-5-194483, U.S. Pat. No.
3,214,463, and like compounds; cinnamic compounds described in
JP-A-48-30492, JP-A-56-21141, JP-A-10-88106, and like compounds;
triazine-based compounds described in JP-A-4-298503, JP-A-8-53427,
JP-A-8-239368, JP-A-10-182621, JP-UM-T-8-501291, and like
compounds; and compounds described in Research Disclosure No. 24239
and compounds which absorb UV radiation and emit fluorescence,
so-called fluorescent brightening agents, and which are typified by
a stilbene-based compound and a benzoxazole-based compound.
[0222] The discoloration inhibitor is used for the purpose of
enhancing the storage characteristics of an image. Various types of
organic-based and metal-based complexes can be used the
discoloration inhibitor. Examples of the organic discoloration
inhibitors include hydroquinones, alkoxyphenols, dialkoxyphenols,
phenols, anilines, amines, indans, chromans, alkoxy anilines,
heterocycles, and the like. Examples of the metal complexes include
nickel complex, zinc complex, and the like. More specifically,
There can be used examples of the metal complexes including
compounds described in Sections I to J of VII in Research
Disclosure No. 17643, compounds described in Research Disclosure
No. 15162, compounds described in the left column on pg. 650 in
Research Disclosure No. 18716, those described on pg. 527 in
Research Disclosure No. 36544, those described on pg. 872 in
Research Disclosure No. 307105, compounds described in patent cited
in Research Disclosure No. 15162, and compounds belong to a formula
of a typical compounds and compound examples described in pp. 127
to 137 of JP-A-62-215272.
[0223] Examples of an antifungal agent include sodium
dehydroacetate, sodium benzoate, sodium pyridinethione-1-oxide,
p-hydroxyethylesterbenzoate, 1,2-benzoisothiazoline-3-ON, and salts
thereof. Preferably, the antifungal agent is used in an amount of
0.02 to 1.00 mass percent.
[0224] The neutralizer (an organic base, inorganic alkaline) can be
used as a pH controlling agent. The pH controlling agent is added
in such a way that inkjet ink assumes a pH value of 6 to 10, and
more preferably a pH value of 7 to 10.
[0225] Examples of the surface tension controlling agent include a
nonionic surface active agent, cationic surfactants, anionic
surfactants, and betainic surfactants. In order to well squirt ink
droplets by means of inkjet action, a preferred amount of surface
tension controlling agent to be added is one at which surface
tension of ink of the present invention is adjusted so as to assume
a value of 20 to 60 mN/m, more preferably 20 to 45 mN/m, further
more preferably 25 to 40 mN/m. Preferred examples of surfactants
include hydrocarbon-based surfactants, including anionic
surfactants and nonionic surfactants. Examples of the anionic
surfactants include fatty acid salts, alkylsulfate ester salts,
alkylbenzenesulfonates, alkylnaphthalenesulfonates, dialkyl
sulfosuccinates, alkyl phosphates, alkyl benzene sulfonates, alkyl
phosphates, condensation products of salts of naphthalenesulfonic
acid with formalin, polyoxyethylene alkylsulfate ester salts, and
the like. Examples of the nonionic surfactants include
polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether,
polyoxyethylene fatty acid ester, sorbitan fatty acid ester,
polyoxyethylene sorbitan fatty acid ester, polyoxyethylene
alkylamine, fatty acid ester of glycerin, oxyethylene oxypropylene
block polymer, and the like. Further, SURFAYNOLS (Air Products
& Chemicals Corporation), which is an acetylenic
polyoxyethylene oxide surfactant, is also preferably used. In
addition, ampholytic surfactants of amine oxide type, such as
N,N-dimethyl-N-alkylamineoxyde, are also preferable. Further,
surfactants described in pp. (37) to (38) of JP-A-58-157636 and
those described in Research Disclosure No. 30819 (1989) can also be
used. Fluorochemical (alkyl-fluoride-based) surfactants and
silicone surfactants, which are described in JP-A-2003-322926,
JP-A-2004-325707, and JP-A-2004-309806, can also be used. These
surface tension controlling agents can also be used as antifoamers,
and Fluorochemical compounds, silicone compounds, and chelating
reagents typified by EDTA can also be used.
[0226] Preferred viscosity of ink for inkjet use of the present
invention is 30 mPas or less. Moreover, the viscosity is preferably
adjusted to a value of 20 mPas or less. An aqueous medium contains
water as the principal component, and a mixture to which a
water-miscible organic solvent is added can be used. Examples of
water-miscible organic solvents include alcohols (e.g., methanol,
ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol,
t-butanol, pentanol, hexanol, cyclohexanol, benzyl alcohol);
polyhydric alcohols (e.g., ethylene glycol, diethylene glycol,
triethyleneglycol, polyethylene glycol, propyleneglycol,
dipropyleneglycol, polypropyleneglycol, butyleneglycol, hexanediol,
pentanediol, glycerin, hexanetriol, and thiodiglycol); glycol
derivatives (e.g., ethylene glycol monomethyl ether, ethylene
glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene
glycol monomethyl ether, diethylene glycol monobutyl ether,
propylene glycol monomethyl ether, propylene glycol monobutyl
ether, dipropylene glycol monomethyl ether, triethylene glycol
monomethyl ether, ethylene glycol diacetate, ethylene glycol
monomethyl ether acetate, ethylene glycol monomethyl ether acetate,
triethylene glycol monomethyl ether, triethylene glycol monoethyl
ether, and ethylene glycol monophenyl ether); amines (e.g.,
ethanolamine, diethanol amine, triethanol, amine,
N-methylethanolamine, N-ethyldiethanolamine, morpholine,
N-ethylmorpholine, ethylenediamine, diethylenetriamine, triethylene
tetramine, polyethylene imine, and tetramethylepropylenediamine);
and other polar solvents (e.g., formamide, N,N-dimethyleformamide,
N,N-dimethylacetamide, dimethylsulfoxide, sulfolane, 2-pyrrolidone,
N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, 2-oxazolidone,
1,3-dimethyl-2-imidazolidinone, acetonitrile, and acetone). Two or
more types of water-miscible organic solvents may be used in
combination.
[0227] The ink for inkjet use of the present invention can be used
for forming a full-color image. In order to form a full-color
image, magenta color ink, cyan color ink, and yellow color ink can
be used. In order to adjust color tones, black color ink may also
be added to the ink. Further, colors of ink other than yellow,
magenta, and cyan colors; namely, red color ink, green color ink,
blue color ink, white color ink, and special colors of ink employed
in a so-called printing field, and the like, can be used.
[0228] An inkjet recorder preferably used in the present invention
will be described. An inkjet recorder 10 shown in FIG. 1 is
equipped with a recording head 12 which emits ink to a sheet 11 to
thus cause ink to adhere to the sheet and record an image. The
recording head 12 has a plurality of nozzles, each of which is
provided with an ejection port used for ejecting ink. An ejection
plane where the ejection ports of the plurality of nozzles are
arranged is arranged so as to oppose a recording plane of the sheet
11. The recording head 12 is attached to a carriage 13 which is
movable with reference to a widthwise direction (a main scanning
direction X) of the sheet 11. The ejection plane is exposed from an
opening formed in the bottom surface of the carriage 13. The
recording head 12 performs line recording to thus record an image
while being reciprocally actuated along the widthwise direction of
the sheet 11 in association with movement of the carriage 13. Every
time the recording head 12 performs a round trip, the sheet 11 is
fed in a sub-scanning direction Y by means of an unillustrated
transport roller by an amount corresponding to a width where
recording is performed by means of a single round trip of the
recording head 12. An image of one screen is recorded through
repetition of these operations.
[0229] The carriage 13 is slidably attached to guide rods 14a, 14b,
and is driven by a belt mechanism 18 formed from a belt 16 and a
pair of pulleys 17. In the carriage 13, four ink cartridges 21
housing, e.g., four colors of ink Y, M, C, K, are removably
attached to a position above the recording head 12. A plurality of
slots into which the respective ink cartridges 21 are to be
inserted are formed in the carriage 13.
[0230] Lower surfaces of the ink cartridges 21 are attached to
floor faces of the slots. When the ink cartridges 21 are attached
to the carriage 13, the ink cartridges 21 and the recording head 12
are connected together by way of ink supply passages. Diaphragms,
which are actuated by means of a piezoelectric element, are
provided in the recording head 12 so as to correspond to the
respective nozzles. Ink in the ink cartridge 21 is sucked to the
nozzle by means of a change in pressure induced by vibration of the
diaphragm, and is emitted from the ejection port.
[0231] During a time other than recording operation, the carriage
13 recedes to a position outside a transport path of the recording
sheet 11, to thus enter a standby condition. The standby position
serves as a home position of the carriage 13, and replacement of
the ink cartridges 21 is performed at this home position. A head
cap 26 is placed at the home position which covers the ejection
plane of the recording head 12 from below to thus receive the ink
having leaked out of the ejection plane. A suction plane 26a used
for sucking clogged ink at the extremity of the nozzle is placed at
a position opposing the ejection plane of the head cap 26. The head
cap 26 is connected to an ejection failure recovery suction pump 27
which sucks the ink clogging the nozzle by way of the suction plane
21a, to thus recover an ejection failure in the recording head 12.
The ink recovered by the suction pump 27 is collected by a recovery
section 28.
[0232] Although FIG. 1 shows an example head of shuttle type, the
present invention can be applied to a line head having a width
equal to that of paper.
[0233] An ink cartridge preferably used in the present invention
will be described. As shown in FIG. 2, the ink cartridge 21 has a
case 34 which stores ink. The case 34 comprises a case main body 32
in which is formed an ink storage chamber 35 used for storing ink;
and a cap member 33 for closing an upper opening of the case main
body 32. The cap member 33 is welded to the case main body 32 such
that ink does not leak from the upper opening after the case main
body 32 has been filled with ink. The case main body 32 is formed
from, e.g., transparent plastic, and the remaining amount of ink in
the ink cartridge 21 can be visually checked.
[0234] An ink absorber 36, which absorbs ink and retains it, is
housed in the ink storage chamber 35. The ink absorber 35 is a
spongy member including minute pores which generate capillary
force. Specifically, various porous materials such as foaming
agents and fibrous materials are used. In the present invention,
polyolefins (resins) are preferably used. The width and depth of
the ink absorber 36 are essentially identical with the width and
depth of the ink storage chamber 35. The ink absorber 36 is housed
while an outer peripheral surface, exclusive of an upper surface,
of the ink absorber remains in contact with an inner wall of the
ink storage chamber 35.
[0235] The case 34 is provided at a location above the recording
head 12, and hence the weight of ink in the case 34 acts as a
positive pressure against the recording head 12. The ink absorber
36 is a negative-pressure generation member which absorbs ink by
means of capillary force, thereby maintaining the internal pressure
of the nozzles of the recording head 12 in a negative pressure
state (with reference to the atmosphere). Thus, the ink in the
recording head 12 is prevented from inadvertently leaking out of
the nozzles.
[0236] An atmosphere inlet port 41 is formed in the cap member 33.
The atmosphere inlet port 41 takes into the ink storage chamber 35
an amount of air equal to that of consumed ink. A bent groove 42 is
formed in an upper surface of the cap member 33. One end 42a of the
groove 42 is connected to the atmosphere inlet port 41, and a
liquid reservoir section 43 is provided in a path from the inlet
port to another end 42b. A top of the groove 42 exclusive of the
other end 42b (i.e., an area between two chain double-dashed lines
in the drawing) is sealed with a seal 45, and only the other end
42b is exposed. When the ink in the ink storage chamber 35 has
leaked out of the atmosphere inlet port 41, the groove 42 guides
the ink to the liquid reservoir section 43, to thus prevent leakage
of ink outside of the ink cartridge 21. Air enters the other end
42b and is guided to the atmosphere inlet port 41.
[0237] A plurality of downwardly-protruding ribs 46 are provided on
a lower surface of the cap member 33. When the cap member 33 is
attached to the case main body 32, the ribs 46 enter the ink
storage chamber 35 and contacts the upper surface of the housed ink
absorber 36, to thus push the ink absorber 36 and press the lower
surface of the ink absorber against the floor of the ink storage
chamber 35. Thus, a space is ensured between the ink absorber 36
and the cap member 33 by means of positioning the ink absorber 36.
The ink absorber 36 is positioned by the ribs 46, and hence closing
of the atmosphere inlet port 41, which would otherwise be caused as
a result of positional displacement of the ink absorber 36, is
prevented.
[0238] An ink output section 51, which withdraws ink from the ink
storage chamber 35 and supplies the ink to the recording head 12,
is provided in the lower surface of the case 34. The ink output
section 51 comprises, for example, an essentially-circular output
port 51a formed in the bottom of the case 34, and a cylindrical
projection section 51b downwardly projecting from the output port
51a. An essentially-plate-like filter 54 is placed at the position
of the output port 51a in the floor of the ink storage chamber 35.
A lower surface (exposed surface) 54a is exposed from the filter 54
through the output port 51a.
[0239] The filter 54 is a mesh filter where a plurality of pores
are arranged in the pattern of a mesh, and filtrates the ink output
to the outside by way of the output port 51a. This filter 54
prevents inflow of, e.g., ink having coagulated in the ink storage
chamber 35 or extraneous matters, into the recording head 12. The
size of the pores of the filter 54 is preferably about 5 .mu.m to
20 .mu.m. Using the filter 54 having such a fine pores reliably
prevents intrusion of extraneous matters, such as dust, into the
ink storage chamber 35 from the outside of the case 34 by way of
the output port 51a.
[0240] However, the fine-meshed filter 54 exhibits high flow
passage resistance during passage of ink, which in turn induces a
loss in suction pressure. For this reason, the ink cartridge 21 and
the inkjet recorder 10, both of which pertain to the present
invention, are provided with a mechanism for lessening the pressure
loss induced by the filter 54 when the ink cartridge 21 is attached
to the inkjet recorder 10.
[0241] A press pin 56 whose one end is fastened to the case 34 and
whose other end extends downwardly to thus become an open end is
provided on the lower surface of the case 34. As will be described
later, the press pin 56 is a press member constituting an ink
pressurization mechanism which pressurizes the ink in the ink
supply passage, thereby generating a countercurrent which flows
toward the case 34 opposite the supply direction toward the
recording head 12, to thus feed ink from the ink supply passage to
the filter 54. By means of feeding ink from the ink supply passage
to the filter 54 in the manner mentioned above, the ink in the ink
supply passage is joined to the ink in the case 34, whereby the
pressure loss induced by the filter 54 is lessened.
EXAMPLES
[0242] More-detailed explanations are provided by means of examples
of the present invention. In the following descriptions, unless
other wise specified, symbol "%" represents a mass standard.
Example 1
Ink-Wetted Member
[0243] An ink tank [having the same shape as that of BCI-3e (model
number: manufactured by Canon Inc.)] was produced by using various
members as ink-wetted members.
[0244] Tank A: a polypropylene tank was molded.
[0245] Tank B: 0.05% of a hydrotalcite compound (DHT-4A
manufactured by Kyowa Chemical Industrial Co., Ltd.), which is
represented by
Mg.sub.1-xAl.sub.x(OH).sub.2(CO.sub.3).sub.x/.sub.2.mH.sub.2O
(0<x.ltoreq.0.5), was mixed as a neutralizer to polypropylene,
and the mixture was kneaded, to thus manufacture pellets. A tank
was molded from the pellets.
[0246] Tank C: 0.01% of calcium stearate was mixed with
polypropylene, and the mixture was kneaded, to thus manufacture
pellets. A tank was molded from the pellets.
[0247] Tank D: 0.2% tris (4-t-butyl-2,6-dimethyl-3-hydroxybenzyl)
isocyanurate was mixed with polypropylene, and the mixture was
kneaded, to thus manufacture pellets. A tank was molded from the
pellets.
[0248] Tank E: 0.2% of bis (m,p-dimethylbenzylidene) sorbitol was
mixed with polypropylene, and the mixture was kneaded to thus
manufacture pellets. A tank was molded from the pellets.
[0249] Tank F: A tank was molded from polyethylene.
[0250] Tank G: 0.05% of hydrotalcite compound (DHT-4A manufactured
by Kyowa Chemical Industrial Co., Ltd.), which is represented by
Mg.sub.1-xAl.sub.x(OH).sub.2(CO.sub.3).sub.x/.sub.2.mH.sub.2O
(0<x.ltoreq.0.5), was mixed as a neutralizer to polyethylene,
and the mixture was kneaded, to thus manufacture pellets. A tank
was molded from the pellets.
[0251] Tank H, 0.01% of calcium stearate was mixed with
polyethylene, and the mixture was kneaded, to thus manufacture
pellets. A tank was molded from the pellets.
[0252] Tank I: 0.2%
tris (4-t-butyl-2,6-dimethyl-3-hydroxybenzyl) isocyanurate was
mixed with polyethylene, and the mixture was kneaded, to thus
manufacture pellets. A tank was molded from the pellets.
[0253] Tank J 0.2% of bis (m,p-dimethylbenzylidene) sorbitol was
mixed with polyethylene, and the mixture was kneaded to thus
manufacture pellets. A tank was molded from the pellets.
[0254] Tanks K to M were formed, as comparative examples of
additives to be added to polypropylene, from lithium aluminum
composite hydroxy compound [LiAl.sub.2
(OH).sub.6].sub.2CO.sub.3.1.6H.sub.2O described in JP-A-10-139941,
and tris-nonylphenylphosphate serving as an organophosphorus
antioxidant and thiodipropionicdilauroylester serving as a
tio-ether-based antioxidant, which are described in
JP-A-10-87907.
[0255] Tank K: 0.05% of lithium aluminum composite hydroxy compound
[LiAl.sub.2 (OH).sub.6].sub.2CO.sub.3.1.6H.sub.2O was mixed with
polypropylene, and the mixture was kneaded to thus manufacture
pellets. A tank was molded from the pellets.
[0256] Tank L: 0.2% of tris-nonylphenylphosphate serving as an
organophosphorus antioxidant was mixed with polypropylene, and the
mixture was kneaded to thus manufacture pellets. A tank was molded
from the pellets.
[0257] Tank M: 0.2% of thiodipropionicdilauroylester serving as a
thioether-based antioxidant was mixed with polypropylene, and the
mixture was kneaded to thus manufacture pellets. A tank was molded
from the pellets.
[0258] (Preparation of Ink Compositions A to H)
[0259] Compositions provided below were mixed such that a total
amount of the compositions assumes a value of 500 parts by mass.
Further, two parts by mass of
2,2'-azobis(2,4-dimethylvaleronitrile) were further added as a
polymerization initiator to the mixture. The mixture was then
subjected to sufficient substitution of a nitrogen gas, whereby
resin blending was obtained.
TABLE-US-00001 Stearyl methacrylate 20 parts by mass Styrene
macromer 5 parts by mass Styrene 10 parts by mass Polypropylene
glycol 10 parts by mass (9) methacrylate Methacrylic acid 10 parts
by mass 2-mercaptoethanol 0.1 parts by mass
[0260] The designations have the following meanings:
[0261] Styrene macromer: manufactured by Toagosei Co., Ltd. Trade
Name: AS-6 (styrene-homopolymerized macromer, a number-average
molecular weight of 6000, Polymeric functional group: a
methacryloyloxymethyl group)
[0262] Polypropylene glycol (9) methacrylate: manufactured by NOF
Corporation, Trade Name: Blenmer-PP-500 (the number of added moles
of propylene oxide: 9)
[0263] 500 parts by mass of methyl ethyl ketone were heated to
75.degree. C. while being stirred at a nitrogen atmosphere. The
resin blending was dropped for four hours in a stirred state at
75.degree. C. Further, the blending was subjected to reaction for
six hours in a stirred state at 75.degree. C. Subsequently, a
reactive component was self-cooled to 25.degree. C., and methyl
ethyl ketone was added so as to dilute the component such that a
solid assumes a value of 50%, whereby a dispersed resin solution
having a mean molecular weight of 19000 was obtained.
[0264] Two parts by mass of 5 mol/L sodium hydroxide solution were
added to 15 parts by mass of 50% of the obtained copolymer
solution, to thus neutralize the copolymer solution. Further, 7.5
parts by mass of Pigment Red 122 [Ciba specialty chemicals, Trade
Name: CROMOPHTAL Jet Magenta DMQ] were added to the solution, and
the mixture was kneaded for two to six hours, as required, by means
of a roll mill. The kneaded product was dispersed in 100 parts by
mass of ion-exchanged water. An organic solvent was completely
removed from the thus-obtained dispersed product at 60.degree. C.
under reduced pressure. Further, water was removed from the
product, whereby the product was condensed. Thus, water dispersion
of pigment-contained vinylpolymer particles whose solid density is
20 mass percent was obtained.
TABLE-US-00002 Water dispersion of 40 parts by mass
pigment-contained vinylpolymer particles Glycerin 8 parts by mass
Diethylene glycol 8 parts by mass Triethanol amine 1 part by mass
Olefin E 1010 (Nissin 1 part by mass Chemical Industry Co., Ltd.)
Triethyleneglycolmonobutylether 8 parts by mass Ion-exchanged water
36 parts by mass
These substances were blended into an ink fluid.
[0265] The ink fluid was subjected to at least one of centrifugal
separation (30 minutes to one hour at 10000 to 20000 rpm, as
required), ultrafiltration, and filtering, to thus separate the ink
fluid. Ink compositions A to H were prepared such that a volumetric
mean particle size of a desired pigment shown in table 1 and a
volume percent of particles of 200 nm or more of the desired
pigment were achieved.
TABLE-US-00003 TABLE 1 VOLUME PERCENT OF INK PARTICLES OF
VOLUMETRIC COMPO- 200 nm OR MEAN PARTICLE SITION MORE SIZE (nm)
REMARKS INK A 5.0 110 COMPARATIVE EXAMPLE INK B 2.2 110 COMPARATIVE
EXAMPLE INK C 2.0 110 PRESENT INVENTION INK D 0.1 110 PRESENT
INVENTION INK E 2.2 70 COMPARATIVE EXAMPLE INK F 2.0 70 PRESENT
INVENTION INK G 2.2 40 COMPARATIVE EXAMPLE INK H 2.0 40 PRESENT
INVENTION
[0266] (Evaluation of Ejection Precision)
[0267] The pigment ink compositions shown in Table 1 were infused
into an ink tank [having the same shape as that of BCI-3e (model
number: manufactured by Canon Inc.)] formed from the wetted member
shown in Table 1. The ink was left for two weeks in an atmosphere
of 70.degree. C. A commercially-available inkjet recording printer
PIXUS 6500i (Trade Name: Canon Inc.) was used as an inkjet
recorder. A 50% Duty solid image was continuously printed on A4 PM
photographic glossy paper (manufactured by Seiko Epson Corporation)
by use of the ink tanks fulfilling the above requirements, until
the amount of consumed ink assumed a value of 10 mL. Continuously,
1,000 droplets were dot-impacted from a single nozzle in the form
of a line. A difference between a target point of impact on a paper
face and the centroid of impacted ink was measured. Standard
deviation was determined from data pertaining to 1000 impacts.
Further, the areas where ink were impacted were measured, to thus
determined standard deviation from data pertaining to 1000 impacts.
The value of standard deviation pertaining to Test 101 was
standardized to 100 and is provided in Table 2. Smaller values
represent preferably small variations.
TABLE-US-00004 TABLE 2 VOLUME % OF VOLUMETRIC VARIATIONS PARTICLES
MEAN VARIATIONS IN TEST PIGMENT OF 200 nm PARTICLE IN POINT OF
IMPACTED NO. INK OR MORE SIZE INK-WETTED MEMBER IMPACT AREA REMARKS
TEST INK B 2.2 110 TANK F: 100 100 COMPARATIVE 101 POLYETHYLENE
EXAMPLE TEST INK B 2.2 110 TANK G: 101 98 COMPARATIVE 102
POLYETHYLENE (WITH EXAMPLE HYDROTALCITE) TEST INK B 2.2 110 TANK H:
99 102 COMPARATIVE 103 POLYETHYLENE (WITH EXAMPLE CALCIUM STEARATE)
TEST INK B 2.2 110 TANK I: 98 101 COMPARATIVE 104 POLYETHYLENE
(WITH EXAMPLE PHENOLIC ANTIOXIDANT) TEST INK B 2.2 110 TANK J: 99
103 COMPARATIVE 105 POLYETHYLENE (WITH EXAMPLE SORBITOL) TEST INK B
2.2 110 TANK A: 102 99 COMPARATIVE 106 POLYPROPYLENE EXAMPLE TEST
INK B 2.2 110 TANK B: 101 98 COMPARATIVE 107 POLYPROPYLENE (WITH
EXAMPLE HYDROTALCITE) TEST INK B 2.2 110 TANK C: 98 102 COMPARATIVE
108 POLYPROPYLENE (WITH EXAMPLE CALCIUM STEARATE) TEST INK B 2.2
110 TANK D: 103 98 COMPARATIVE 109 POLYPROPYLENE (WITH EXAMPLE
PHENOLIC ANTIOXIDANT) TEST INK B 2.2 110 TANK E: 100 102
COMPARATIVE 110 POLYPROPYLENE (WITH EXAMPLE SORBITOL) TEST INK C
2.0 110 TANK F: 98 101 COMPARATIVE 111 POLYETHYLENE EXAMPLE TEST
INK C 2.0 110 TANK G: 92 93 PRESENT 112 POLYETHYLENE (WITH
INVENTION HYDROTALCITE) TEST INK C 2.0 110 TANK H: 93 92 PRESENT
113 POLYETHYLENE (WITH INVENTION CALCIUM STEARATE) TEST INK C 2.0
110 TANK I: 90 94 PRESENT 114 POLYETHYLENE (WITH INVENTION PHENOLIC
ANTIOXIDANT) TEST INK C 2.0 110 TANK J: 92 93 PRESENT 115
POLYETHYLENE (WITH INVENTION SORBITOL) TEST INK C 2.0 110 TANK A:
101 98 COMPARATIVE 116 POLYPROPYLENE EXAMPLE TEST INK C 2.0 110
TANK B: 85 84 PRESENT 117 POLYPROPYLENE (WITH INVENTION
HYDROTALCITE) TEST INK C 2.0 110 TANK C: 86 86 PRESENT 118
POLYPROPYLENE (WITH INVENTION CALCIUM STEARATE) TEST INK C 2.0 110
TANK D: 84 86 PRESENT 119 POLYPROPYLENE (WITH INVENTION PHENOLIC
ANTIOXIDANT) TEST INK C 2.0 110 TANK E: 86 84 PRESENT 120
POLYPROPYLENE (WITH INVENTION SORBITOL) TEST INK C 2.0 110 TANK K:
101 100 COMPARATIVE 121 POLYPROPYLENE (WITH EXAMPLE LITHIUM
ALUMINUM COMPOSITE HYDROXY COMPOUND) TEST INK C 2.0 110 TANK L: 99
101 COMPARATIVE 122 POLYPROPYLENE (WITH EXAMPLE ORGANOPHOSPHOROUS
ANTIOXIDANT) TEST INK C 2.0 110 TANK M: 98 102 COMPARATIVE 123
POLYPROPYLENE (WITH EXAMPLE THIOETHER-BASED ANTIOXIDANT)
[0268] As can be seen from Tests 101 to 110, the evaluation of
precision of ink ejection achieved by use of pigment ink B (the
volume percent of particles of 200 nm or more in a pigment is 2.2%)
after the ink had been stored at high temperature shows that
influence imposed on the precision of ejection of polyethyelens and
polypropylenes, which were employed as the ink-wetted members, can
be said to be small. As can be seen from Tests 111 and 116, even
when ink C whose volume percent of particles of 200 nm or more in a
pigment is 2.0% or less was used as pigment ink, influence imposed
on the precision of ejection is understood to be small in a case
where the ink-wetted members are polyethylene and polypropylene.
However, Tests 112 to 115 and Tests 117 to 120 show that, when ink
C whose volume percent of particles of 200 nm or more in a pigment
is 2.0% or less was used as pigment ink and when polyethylenes and
polypropylenes of the present invention were used as ink-wetted
members, the precision of ejection is understood to have been
improved significantly. As can be seen from Tests 121 to 123, a
combination of the polypropylenes with additives, which do not
belong the present invention, with the ink whose volume percent of
particles of 200 nm or more in a pigment is 2% or less, which
belongs to the present invention, is not effective.
TABLE-US-00005 TABLE 3 VOLUME % OF VOLUMETRIC PARTICLES MEAN
VARIATIONS VARIATIONS TEST PIGMENT OF 200 nm PARTICLE IN POINT OF
IN IMPACTED NO. INK OR MORE SIZE (nm) INK-WETTED MEMBER IMPACT AREA
REMARKS TEST INK B 2.2 110 TANK F: 100 100 COMPARATIVE 201
POLYETHYLENE EXAMPLE TEST INK B 2.2 110 TANK A: 102 99 COMPARATIVE
202 POLYPROPYLENE EXAMPLE TEST INK B 2.2 110 TANK B: 101 98
COMPARATIVE 203 POLYPROPYLENE EXAMPLE (WITH HYDROTALCITE)) TEST INK
C 2.0 110 TANK F: 98 101 COMPARATIVE 204 POLYETHYLENE EXAMPLE TEST
INK C 2.0 110 TANK A: 101 98 COMPARATIVE 205 POLYPROPYLENE EXAMPLE
TEST INK C 2.0 110 TANK B: 85 84 PRESENT 206 POLYPROPYLENE
INVENTION (WITH HYDROTALCITE) TEST INK A 5.0 110 TANK F: 130 115
COMPARATIVE 207 POLYETHYLENE EXAMPLE TEST INK A 5.0 110 TANK A: 133
112 COMPARATIVE 208 POLYPROPYLENE EXAMPLE TEST INK A 5.0 110 TANK
B: 129 113 COMPARATIVE 209 POLYPROPYLENE EXAMPLE (WITH
HYDROTALCITE) TEST INK D 0.1 110 TANK F: 98 101 COMPARATIVE 210
POLYETHYLENE EXAMPLE TEST INK D 0.1 110 TANK A: 97 100 COMPARATIVE
211 POLYPROPYLENE EXAMPLE TEST INK D 0.1 110 TANK B: 83 82 PRESENT
212 POLYPROPYLENE INVENTION (WITH HYDROTALCITE) TEST INK E 2.2 70
TANK F: 97 99 COMPARATIVE 213 POLYETHYLENE EXAMPLE TEST INK E 2.2
70 TANK A: 96 101 COMPARATIVE 214 POLYPROPYLENE EXAMPLE TEST INK E
2.2 70 TANK B: 97 102 COMPARATIVE 215 POLYPROPYLENE EXAMPLE (WITH
HYDROTALCITE) TEST INK F 2.0 70 TANK F: 99 101 COMPARATIVE 216
POLYETHYLENE EXAMPLE TEST INK F 2.0 70 TANK A: 97 98 COMPARATIVE
217 POLYPROPYLENE EXAMPLE TEST INK F 2.0 70 TANK B: 84 83 PRESENT
218 POLYPROPYLENE INVENTION (WITH HYDROTALCITE) TEST INK G 2.2 40
TANK F: 101 99 COMPARATIVE 219 POLYETHYLENE EXAMPLE TEST INK G 2.2
40 TANK A: 100 102 COMPARATIVE 220 POLYPROPYLENE EXAMPLE TEST INK G
2.2 40 TANK B: 98 98 COMPARATIVE 221 POLYPROPYLENE EXAMPLE (WITH
HYDROTALCITE) TEST INK H 2.0 40 TANK F: 99 100 COMPARATIVE 222
POLYETHYLENE EXAMPLE TEST INK H 2.0 40 TANK A: 98 97 COMPARATIVE
223 POLYPROPYLENE EXAMPLE TEST INK H 2.0 40 TANK B: 86 83 PRESENT
224 POLYPROPYLENE INVENTION (WITH HYDROTALCITE)
[0269] As can be seen from Tests 201 to 203, 207 to 209, 213 to
215, and 219 to 221, when pigment ink B, ink A, ink E, and ink G,
whose volume percent of particles of 200 nm or more in a pigment is
2% or more, were used, evaluation of precision of ink ejection
achieved after ink had been stored at high temperatures shows that
influence imposed on the precision of ejection of polyethylenes and
polypropylenes, which were employed as the ink-wetted members, can
be said to be small. As can be seen from Tests 204, 205, 210, 211,
216, 217, 222, and 223, even when ink whose volume percent of
particles of 200 nm or more in a pigment is 2.0% or less was used
as pigment ink, influence imposed on the precision of ejection is
understood to be small in a case where the ink-wetted member is
polyethylene and polypropylene. However, as can be seen from Tests
206, 212, 218, and 224, when polypropylenes of the present
invention were used as the ink-wetted members by using ink whose
volume percent of particles of 200 nm or more in a pigment is 2.0%
or less as pigment ink, the precision of ejection is understood to
have been improved significantly. From the above, the volumetric
mean particle size of a pigment does not affect the precision of
ejection of ink, but volume percent of particles of 200 nm or more
in a pigment is 2.0% or less is understood to be important.
Example 2
[0270] Ink to which 2% of a water-soluble planar compound P-1 was
added was prepared as an ink composition. Addition/non-addition of
the compound is provided in Table 4.
TABLE-US-00006 TABLE 4 VOLUME % OF VOLUMETRIC WATER- PARTICLES MEAN
SOLUBLE VARIATIONS VARIATIONS TEST PIGMENT OF 200 nm PARTICLE
INK-WETTED PLANAR IN POINT OF IN IMPACTED NO. INK OR MORE SIZE (nm)
MEMBER COMPOUND IMPACT AREA REMARKS TEST INK B 2.2 110 TANK F: NONE
100 100 COMPARATIVE 301 POLYETHYLENE EXAMPLE TEST INK B 2.2 110
TANK B: NONE 101 98 COMPARATIVE 302 POLYPROPYLENE EXAMPLE (WITH
HYDROTALCITE) TEST INK C 2.0 110 TANK F: NONE 98 101 COMPARATIVE
303 POLYETHYLENE EXAMPLE TEST INK C 2.0 110 TANK B: NONE 85 84
PRESENT 304 POLYPROPYLENE INVENTION (WITH HYDROTALCITE) TEST INK B
2.2 110 TANK F: (WITH 2% OF) 101 103 COMPARATIVE 305 POLYETHYLENE
COMPOUND P-1 EXAMPLE TEST INK B 2.2 110 TANK B: (WITH 2% OF) 99 101
COMPARATIVE 306 POLYPROPYLENE COMPOUND P-1 EXAMPLE (WITH
HYDROTALCITE) TEST INK C 2.0 110 TANK F: (WITH 2% OF) 99 98
COMPARATIVE 307 POLYETHYLENE COMPOUND P-1 EXAMPLE TEST INK C 2.0
110 TANK B: (WITH 2% OF) 82 80 PRESENT 308 POLYPROPYLENE COMPOUND
P-1 INVENTION (WITH HYDROTALCITE)
[0271] As can be seen from a comparison between Tests 201 to 204
and Tests 205 to 208, when ink B whose volume percent of particles
of 200 nm or more in a pigment is 2.0% or more is used as ink and
when the ink-wetted member is polyethylene, addition of a
water-soluble planar compound to ink is understood to exhibit small
influence. In the case of ink C whose volume percent of particles
of 200 nm or more in a pigment is 2.0% or less and the ink-wetted
members, both of which belong to the present invention, addition of
the water-soluble planar compound to ink is understood to enhance
the precision of ejection.
Example 3
[0272] Evaluation was made under the conditions for Example 1 and
Example 2 by means of replacing CI Pigment Red-122 employed as a
pigment in Examples 1 and 2 with CI Pigment Yellow-12, Cl Pigment
Yellow-17, CI Pigment Yellow-55, CI Pigment Yellow-74, CI Pigment
Yellow-97, CI Pigment Yellow-120, CI Pigment Yellow-128, CI Pigment
Yellow-151, CI Pigment Yellow-155, and CI Pigment Yellow-180; CI
Pigment Violet-19; CI Pigment Red-57:1, CI Pigment Red-146; and CI
Pigment Blue-15:3. As a result, superior performance was exhibited,
as in the case of Compound 1.
Example 4
[0273] Pigment ink whose volume percent of particles of 200 nm or
more in a pigment is 1.0% or less and pigment ink whose volume
percent of particles of 200 nm or more in a pigment is 0.5% or less
were prepared. These two types of ink were evaluated under the
conditions for Examples 1 to 3. The pigment ink whose volume
percent of particles of 200 nm or more in a pigment is 1.0% or less
was ascertained to exhibit superior performance when compared with
whose volume percent of particles of 200 nm or more in a pigment is
2.0% or less. Pigment ink whose volume percent of particles of 200
nm or more in a pigment is 0.5% or less was ascertained to have
exhibited much superior performance.
Example 5
[0274] Tanks were prepared from polyacetal, unsaturated polyester,
PS, PET, and PVC for comparative tests of the ink-wetted members,
and the tanks were evaluated under the conditions for Examples 1
and 2. A combination of the members with the pigment ink whose
volume percent of particles of 200 nm or more in a pigment is 2% or
less showed no improvement in ejection precision.
Example 6
[0275] In relation to the ink absorber complying with the ink tank
[BCI-3e (model number: manufactured by Canon Inc.)], ink absorbers
were prepared from the same ink-wetted members as those of the
tanks A to M of Example 1. Tests analogous to those of Example 1
were conducted, whereby a combination of the pigment ink whose
volume percent of particles of 200 nm or more in a pigment is 2% or
less with the ink-wetted members of the present invention showed
superior ejection accuracy.
[0276] By means of configuration of the present invention, when ink
having remained in contact with the wetted member used in the
inkjet recorder for a long period of time and at a
comparatively-low temperature or for a short period of time and at
a comparatively-high temperature, variations in the volume of
ejected ink and displacement of ink from a target point of impact
can be reduced.
[0277] The entire disclosure of each and every foreign patent
application from which the benefit of foreign priority has been
claimed in the present application is incorporated herein by
reference, as if fully set forth.
* * * * *